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Online ISSN: 1383-4517
The endemic Javan hawk-eagle Spizaetus bartelsi is considered threatened with extinction because of its small population size and fragmentation of its habitat on the densely populated island of Java, Indonesia. Like many other tropical forest raptors little is known about many of its population parameters. Research was carried out from 1980 to 2000 in order to assess the status of this species. Its presence was confirmed throughout the island in both wet and dry climatic zones. Home range sizes were calculated to range between 12-36 km2, and comparison with published estimates suggests that these may differ significantly between areas. Encounter rates are in the order of 0.1-0.9 birds per survey day, and were significantly higher in areas with a short dry season compared to areas with a long dry season. Based on field-observations, museum skins and captive birds, the adult: non adult ratio is 1: 1.3. An assessment of habitat quality for all large areas where Javan hawk-eagles have been recorded, and a conservative working density differentiated to habitat quality, lead us to estimate that there are 137-188 remaining pairs, which account for a total world population of just short of a thousand birds. We make a number of suggestions for further research aimed at obtaining more insight on dispersal, recruitment and age-related habitat preferences, and for improved conservation, including more strict law enforcement and gazettment of new reserves.
Environmental variables and corresponding units 
Jackknife analysis of the importance of the variables used for the models of the four species with all occurrence localities included. Regularized training gain is given for the variable alone. The higher the gain of a variable when it is used alone, the more useful it is in predicting the spe- cies' distribution. Species names abbreviated by initials.
the models based on sub-sampling occurrence localities. Abbreviations: a: model with one occurrence locality omitted; b: model with ten occurrence localities omitted.
This paper aims at modelling the spatial distribution of the cockroach species Capraiellus panzeri, Ectobius lapponicus, Ectobius pallidus and Ectobius sylvestris within the Netherlands and comparing the habitat preferences of these species. Maxent was used to calculate habitat suitability and to identify environmental variables underlying the differences in observed distribution patterns. A sub-sampling procedure was employed to test model stability. Models were evaluated by calculating the Area Under the Curve (AUC). The analyses show that except for the coastal dune area, the western part of the Netherlands is unsuitable for the species. Suitability predictions for C. panzeri, E. lapponicus and E. sylvestris are very similar, with suitable areas concentrated in the eastern and the north-eastern parts of the country and along the western coast. The prediction model for E. pallidus is somewhat more restricted, especially in the northern part of the country. Soil type, land cover and altitudinal range are most important in predicting the distribution of all species. A correspondence analysis was performed to identify the association between the species distribution and the most influential environmental variables. Correspondence analysis indicated that the species distributions are comparably associated with soil type and land cover while species appear to have different preferences with respect to altitudinal range.
A biometric study of chelae of the burrowing shrimp Protocallianassa faujasi (Desmarest, 1822), from the late Maastrichtian of the type Maastrichtian area, the Netherlands, has revealed three morphotypes.
Pugilina erecta n. sp., Auban outcrop, Lower Miri Fm. Fig. 6 Holotype km 3.55, RMNH: H 47.5 mm. Figs. 7-8 Paratypes 2-3 km 3.45, R F5136: H 57.5+ mm and 62.1 mm. Fig. 9 Paratype 4 Auban outcrop lower part of section, R F4023: H 51.8 mm. 
Volema goliath. Fig 17 Holotype, Auban outcrop km 3.65, Lower Miri Fm, RMNH: H 65.7+ mm, W 83.8 mm; Fig. 18 Paratype, Tutong sample 11B, NE of Tutong, Miri Fm, RMNH: H 25.2, W 19.4 mm. Figs. 19-23. Volema myristica. Fig. 19 East of Kampung Tengah turnoff near Bekenu, Sibuti Fm, Setap Shale, R F4141: H 30.7 mm. Figs 20-21 Auban outcrop km 4.35, Middle Miocene, Lower Miri Fm, F4198. Fig. 2, H 32.7 mm. Fig. 3, H 14.1 mm. Fig. 22 300 m SE of Canada Hill, Miri, Holocene, R H1112: H 40.7 mm. Fig. 23 Kampung Pohon Batu, Labuan Island, Recent, R T3137: part of group of shells of various species eaten by men, 54.1 mm. Fig. 24. Volema n. sp., to be described by Kurihara & Kase (pers. comm. to GJV, Oct, 2008), Auban outcrop lower part of section, Lower Miri Fm, R F4109: H 54.3+ mm. 
Melongena murifactor n. sp. East of Kampung Tengah turnoff near Bekenu, Sibuti Fm, Setap Shale. Fig. 1 Holotype, RMNH: H 65.7 mm; Fig. 2 Paratype, R F4071: H 43.5 mm. Figs. 3-5. Melongena gigas. Fig. 3 Auban outcrop, km 2.68 km, Lower Miri Fm, R F5142: H 25 cm. Fig. 4 Auban outcrop km 3.7, Lower Miri Fm, R F5123: W 132 mm. Fig. 5 Penanjong Beach (on beach itself), Seria or Liang Fm, coll. CL.
Pugilina ickei. Fig. 10 Auban outcrop km 0.6, Lower Miri Fm, R F5140: H 51.6 mm. Fig. 11 Tutong sample 11B, Miri Fm, RMNH: H 26.3 mm. Figs 12-13. Pugilina spec. A East of Kampung Tengah turnoff near Bekenu, Sibuti Fm, Setap Shale, R F4089. Fig. 12 H 54.6 mm. Fig. 13 H 47.4 mm. Fig. 14. Pugilina cochlidium. Tanjing Lobang, Miri, Recent, R T1732: H 89.4 mm. Figs. 15-16. Hemifusus ternatanus. Fig. 15 Piasau Beach, Miri, Recent, R T0613: H 87.4 mm. Fig. 16 Sungei Boang, Miri, Holocene, R H1489: H 109.6 mm.
In this paper the Miocene to recent melongenid species of northwest Borneo are discussed. The recent fauna is poor with three genera represented by one species each. In the Miocene three (possibly four) genera occur with eight (possibly nine) species of which three are described as new species: Melongena murifactor, uniquely characterized by the formation of a septum walling off the adapical sector of the aperture; Pugilina erecta, characterized (along with its close Miocene relative from Java, P. ickei) by a free-edged, erect inner lip; Volema goliath, large for the genus with later whorls progressively covering the upper row of spines of earlier whorls. The apertural septum of M. murifactor is unique within Gastropoda, whereas the erect inner lip of P. erecta and P. ickei is unique within Melongenidae. That these extralimital traits occur exclusively in the Miocene of southeast Asia is consistent with the hypothesis that adaptive innovations are most likely to arise in diverse, productive, shallow-water ecosystems.
Collection sites of brook lampreys in Portugal (circles). Circles are filled according to the clades recognized in Mateus et al. (2011b). Site locations: 1, river Esmoriz; 2, river Vouga; 3, river Lis; 4, Ribeiras do Oeste; 5, river Nabão; 6, river Sado.
Scheme of the morphometric measurements and meristic counts used to examine morphological variation of adult brook lampreys. Variables: Tl, total length; d, disc length; d-O, preocular length; O, eye diameter; O-B 1 , postocular length; d-n, prenostril length; hco, head depth; io, interocular distance; HW, head width; d-B 1 , prebranchial length; B 1 -B 7 , branchial length; d-B 7 , head length; d-D 1 , predorsal distance; d-D 2 , distance between disc and base of second dorsal fin; D 2 -C, dorsal part of caudal fin length; lD 1 , first dorsal fin length; lD 2 , second dorsal fin length; H, body depth; B 7 -C, postbranchial length; AR, anterial rows; SO, supraoral lamina; LC, lateral circumorals or endolaterals; IL, infraoral lamina.
Geographic distribution (■) of (A) Lampetra alavariensis sp. nov., (B) Lampetra auremensis sp. nov., (C) Lampetra lusitanica sp. nov. and (D) Lampetra planeri in Portugal.
Eigenvalues and percentage of variance of the four dis- criminant functions attained in the stepwise discriminant anal- ysis.
Classification results attained with the stepwise discriminant analysis cross-validation for morphometric characters. The table must be read horizontally.
The Iberian Peninsula is a repository for biodiversity, present-ing high levels of endemism in both plants and animals. In this peninsular region, brook lampreys confined to small, isolated river basins evolved in allopatry giving rise to evolutionary lin-eages, as revealed by mitochondrial DNA markers. For a better understanding of the taxonomic status and relationships of Ibe-rian populations of the genus Lampetra, we combined previous data from genetics and morphological analysis (assessed here), and describe three new species of the lamprey genus Lampetra Bonnaterre, 1788 in Portugal. In this region L. planeri actually represent a complex of cryptic species, each having smaller geographic ranges than L. planeri, and consequently, greater vulnerability to extinction. The description of Lampetra ala-variensis sp. nov. is based on 36 specimens collected on Ribeira de Mangas, a tributary of river Esmoriz, in Northern Portugal. Lampetra auremensis sp. nov. is described on the basis of 31 specimens collected on Ribeira do Olival, a small tributary of river Nabão (Tagus basin). Finally, Lampetra lusitanica sp. nov. is described based on 38 specimens from Ribeira da Marateca, Sado river basin, the southernmost distribution of the genus Lampetra. The recognition of these new species will contribute to the conservation of these already imperilled taxa and will help prevent the extinction of three important evolutionary line-ages.
The life cycle of the gorgonian Eunicella singularis has been studied with emphasis on larval behaviour, metamorphosis and annual growth. Planulae are found to have a mobile phase lasting from several hours to several days. Once settled, they metamorphose into a complete primary polyp in approximately four days. In the first year, budding will yield colonies of a height between 10 and 30 mm. Subsequently, average growth rates range from 14 to 33 mm year ⁻¹ . Death may be due to several causes. Predators may partly denude the gorgonian branches, thus facilitating the settlement of epibionts, which in turn may invade the entire skeleton, slowly pushing back the living tissue of the gorgonian. Colonies may also be torn off their substratum by wave or current action, this process sometimes being speeded up when tall epibionts such as fast growing bryozoans enhance resistance to water movement. Once toppled, the gorgonians die by necrosis of their living tissues, or by being buried under sediment. Colonies of E. singularis are estimated to reach an age of approximately 25 to 30 years. Some data have been obtained on growth rates and life spans of two other Mediterranean gorgonians, Lophogorgia ceratophyta and Paramuricea clavata .
GPS coordinates, altitude (masl; meters above sea level), flow rate (ms -1 ; meters per second), number of samples, min-max. length and weight of Schizothorax richardsonii across the Indian Himalaya.
Percentage of specimens classified in each group and after cross validation for morphometric measurements of Schizo- thorax richardsonii from four rivers across Indian Himalaya (86.6% of original grouped cases correctly classified, 82.9% of cross-validated grouped cases correctly classified).
Results of Wilks' lambda tests of the discriminant func- tion analysis (function 1 through 3) of morphometric variables of Schizothorax richardsonii collected from four rivers across Indian Himalaya.
Contribution to discriminant functions (DFs) of mor- phometric variables of Schizothorax richardsonii collected from four rivers across Indian Himalaya. *indicates largest absolute correlation between each variable and any discriminant func- tion.
We investigated intraspecific variation of the Snowtrout, Schizothorax richardsonii on the basis of morphometric characters. Altogether, 217 specimens were collected from four rivers in the Western and Central Indian Himalaya. A truss network was constructed by interconnecting 14 landmarks to yield 31 distance variables that were extracted from digital images of specimens using tpsDig2 and PAST software. Transformed truss measurements were subjected to univariate analysis of variance, factor analysis and discriminant analysis. All variables exhibited significant differences between the populations. Altogether 86.6% of the specimens were classified into their original populations (82.9 % under a 'leave-one-out' procedure). With factor analysis measurements of the head region, the middle portion and the caudal region had high loadings on the on first and second axis. The results indicated that S. richardsonii has significant phenotypic heterogeneity between the Western and Central Indian Himalayas. We hypothesize that the marked interspecific variation in S. richardsonii is the result of local ecological conditions.
Digitalized landmarks on antenna (A) and leg (C) of the species M. unilineatum are shown, as well as digitalized landmarks and semi-landmarks on its head (B), promere (D), and opisthomere (E). See supplementary text S1 for descriptions of landmarks and semi-landmarks.
Individuals of both sexes and sequences of sexual behaviour in M. unilineatum. A -male; B -female; C, D, E -contact; F, G, H, I, J, K -extrusion of gonopods (arrows); L, M, N -copulation. photo by B. Ilić
Morphological variation of body mass (A), body length (B), antennal length (C), walking leg length (D), trunk width (E), and trunk height (F) between males and females with different mating status. Morphological variation of flagellum length (fl) between mated and non-mated males (G) is also depicted. The median with the first and the third quartiles is shown (in boxes), together with the range of variation and outliers.
Although morphological variation may have an effect on behaviour, there are only a few studies on julid millipedes in which the influence of the variability of some morphological traits on mating success has been explored. Hence, objectives of this study were to investigate mating behaviour in laboratory conditions and identify traits that could possibly be the target of pre-copulatory selection in the julid species Megaphyllum unilineatum . Behavioural sequences were quantified in three types of tests: a mating arena test, a female choice test, and a male choice test. Although the number of contacts with the first chosen partner (from the mating arena test) was greater than with newly offered individuals in choice tests, values of the sexual selection coefficient did not statistically confirm this preference. In addition, analyses of linear measurements (trunk height and width, length of the whole body, antennae, walking legs, and gonopod flagella) in individuals of different mating status were also conducted, as well as geometric morphometric analyses of size and shape of the antennae, heads, walking legs, and gonopod promeres and opisthomeres in such individuals. Antennal length and shape, head shape, and the walking legs shape, differed significantly, depending on the mating status of females. In males of different mating status, statistical significance was established only in the promere centroid size. The differences in certain behavioural sequences in M. unilineatum are similar to those previously reported in M. bosniense , while such similarity is not detected with respect to morphological variation in the mentioned species.
Invasions of alien species form one of the major threats to global biodiversity. Among planarian flatworms many species are known to be invasive, in several cases strongly affecting local ecosystems. Therefore, a detailed knowledge on the biology of an invasive species is of utmost importance for understanding the process of invasion, the cause of its success, and the subsequent ecological impact on native species. This paper provides new information on the biology of introduced populations of the freshwater flatworm Girardia tigrina (Girard, 1850) from Europe. This species is a native of the Nearctic Region that was accidentally introduced into Europe in the 1920s. Since then, numerous records across the European continent bear witness of the invasiveness of this species, although only a few studies focused on the biology of the introduced populations. We report on the morphology of sexualized individuals from a fissiparous Italian population, representing the second record of spontaneous sexualization of fissiparous individuals in this species. A detailed morphological account of the reproductive apparatus of these ex-fissiparous animals is presented. Our results increased the number of morphological groups previously recognized for European populations of G. tigrina, thus corroborating the hypothesis on multiple independent introductions to this continent. Karyological results obtained from our fissiparous Italian individuals revealed a constant diploid chromosome complement of sixteen chromosomes. Further, we document the marked intraspecific variation in several morphological features of this species.
50% majority rule consensus cladogram produced from Bayesian analysis of COI data. Bayesian posterior probabilities are shown at each node.
Maximum-likelihood tree based on the combined dataset (COI, 28S, and 18S) using Garli v.2.1.17 and the structural alignment for 28S and 18S. Bootstrap support values (above) and Bayesian posterior probabilities (below) are depicted at the nodes (only >50 or >0.5, respectively). BS = Bootstrap support values; PP = Bayesian posterior probabilities.
A-B: Melanostoma sp. from Cameroon (ZFMK-DIP-00015959) with complete metasternum. A, lateral view; B, habitus. C-H: Platycheirus solitarius (van Doesburg, 1955) comb. nov. C, female holotype, lateral view; D, female holotype, habitus; E, female holotype, frontal view; F, female holotype, labels; G, female paratype, lateral view; H, female paratype, head, lateral view. Downloaded from Brill.com12/29/2019 12:39:20PM
A-B: Melanostoma quadripunctatum (Skevington & Thompson, 2014) comb. nov., male holotype. A, lateral view; B, habitus. C, Melanostoma janeceki Mengual, sp. nov., male holotype, ventral view. D, Melanostoma janeceki Mengual, sp. nov., male paratype (ZFMK-DIP-00015941), detail of metasternum (ms). E, Melanostoma janeceki Mengual, sp. nov., female paratype (ZFMK-DIP-00015957), ventral view. F, Melanostoma quadripunctatum, female (ZFMK-DIP-00015952), ventral view.
The phylogenetic relationships among the genera of the tribe Bacchini sensu lato (i.e., Syrphinae with simple, unsegmented aedeagus) were inferred using molecular evidence. The mitochondrial protein-coding gene cytochrome c oxidase subunit I (COI) and the nuclear ribosomal 28S and 18S rRNA genes for 54 bacchine taxa were analyzed using Bayesian inference and Maximum Likelihood. Among the analyzed taxa there is a new species of Melanostoma (Schiner) from Cameroon, Melanostoma janeceki Mengual, sp. nov. , which is described in full. This new species has a complete metasternum without excavation, a characteristic that is not present in other species of Melanostoma , usually with an excavated metasternum, but it is the diagnostic character of the genus Afrostoma Skevington, Thompson & Vockeroth. Based on the phylogenetic placement of Melanostoma janeceki Mengual, sp. nov. the taxonomic status of Afrostoma as a genus is discussed and a new generic classification of Bacchini stat. rev. and Melanostomini stat. rev. is presented in the light of the inferred phylogeny. Results did not recover Bacchini sensu lato monophyletic, but into two groups as follows: Melanostoma and related genera, and Baccha , Platycheirus and related genera. Pseudoplatychirus van Doesburg is considered junior synonym of Platycheirus Le Peletier & Audinet-Serville, and Afrostoma Skevington, Thompson & Vockeroth as junior synonym of Melanostoma . Pyrophaena Schiner and Eocheilosia Hull comb. nov. are ranked as valid genera, and consequently, the genus Platycheirus is divided into four subgenera: Platycheirus (Carposcalis) (Enderlein), Platycheirus (Pachysphyria) (Enderlein), Platycheirus (Platycheirus) , and Platycheirus (Tuberculanostoma) (Fluke) comb. nov.
Surveys of the freshwater crabs of two islands in the Gulf of Guinea, Central Africa, allowed a revision of the taxonomy of two little-known island endemic species, based for the first time on adult males: Potamonautes margaritarius (A. Milne-Edwards, 1869) from São Tomé, and of P. principe Cumberlidge, Clark and Baillie, 2002, from Príncipe (Brachyura; Potamonautidae). A new species of Potamonautes from southern São Tomé ( Potamonautes saotome sp. nov.) is also described that is genetically distinct and has a clearly separate geographic distribution from P. margaritarius from northern São Tomé. The new species from southern São Tomé can be recognized by a suite of characters of the carapace, thoracic sternum, and gonopods. The taxonomy of P. margaritarius (A. Milne-Edwards, 1869) is stabilized by selecting a neotype from northern São Tomé. Potamonautes principe from Príncipe is the most distinct of the three taxa, with a more swollen carapace that has smooth anterolateral margins, and a shorter, straighter male first gonopod. All three taxa are morphologically distinct species that have also been clearly distinguished as evolutionarily separate lineages by mtDNA analysis and haplotyping in an earlier study. Previous phylogenetic evidence supports two separate island colonization events at different times in the past from different ancestral populations, one to São Tomé and another to Príncipe that resulted in the establishment of the endemic freshwater crab faunas of these two islands.
Map of the translocations of the Dama dama mesopotamica and its hybrids with European fallow deer. Tags for sites: Ashk Island (A), Dez River (B) at the Kareheh area, Semeskandeh Wildlife Refuge (C) and Dasht-e-Naz Wildlife Refuge (D) at Mazandaran, Arjan Protected Area (E) at Fars in Iran; the Hai Bar Nature Reserve (H) in Israel and the Von Opel Zoo (O) in Germany. B to O arrow signals the first and the second of the translocations to the captive breed-ing core in Germany (1957/58 and 1964). B to D/C and A/E arrows to mark those translocations during the first conservation actions (1964/67) and posterior conservation measures (1976/77), respectively, in Iran. To refer to translocations of hybrids (1973) see arrow O to D. Finally, the translocations of pureblood from Germany (1976) and Iran (1979) to Israel is showed by the arrows O to H and D to H, respectively.
The proportion of the individual fallow deer genotypes from the four samples (A) K= 2 (modal K) and (B) K= 3 clusters. Legends indicate the coded groups as in Table 1 (left) and the taxonomic name of subspecies (right).
The Persian fallow deer (Dama dama mesopotamica) formerly widespread in the Middle East was described scientifically at the end of the 19th century and considered extinct ever since. In 1956 it was rediscovered in south-western Iran. As a result, several countries have undertaken actions to reintroduce this subspecies in its native territory. In 2007 the Christian Oswald Foundation, in close cooperation with Iranian institutions, launched plans of in situ and ex situ breeding actions, with its centre in the German Von Opel Zoo and with cooperative Mediterranean partner countries as Israel, to support conservation efforts under scientific control. We performed genetic studies to study the suspected hybridization with European fallow deer (Dama dama dama) and a commitment to preserve pureblood populations. We used a set of microsatellite loci to examine genetic variation and recent hybridization with the European fallow deer. All microsatellite loci used were polymorphic, but some were monomorphic within subspecies. The allelic richness was similar in both subspecies but the 'private allelic richness' was reduced to a half in the Persian fallow deer, signalling allelic loss due to genetic drift and inbreeding. Moreover, we showed the presence of two discrete groups representing the two subspecies, with no signs of admixture or hybridization. Furthermore, Persian fallow deer studied here belong to two pre-defined genetics groups: the wild and the (more genetically impoverished) captive populations of Persian fallow deer. Finally, the Persian fallow deer deserves a high conservation priority, both in the Iranian stock and in the captive populations, so as to avoid hybridization.
Maximum likelihood phylogram of sea anemones closely related to Heteranthus verruculatus. Topology presented consists of a concatenated dataset (i.e., cox3, 12S, 16S, 28S). Bootstrap resampling values under ml, and posterior probability values of Bayesian Inference (bi), are indicated at the branches as ml/bi. Only bootstrap values ≥50 and posterior probability ≥0.8 are shown; values <50 and <0.8 are indicated by (-). Text in parentheses are catalogue numbers for tissue samples of new sequences in this study (see supplementary table S1); (*) denotes H. verruculatus sample collected from Australia, previously published in González-Muñoz et al. (2015). For full tree, refer to supplementary fig. S2.
Living specimens of Heteranthus verruculatus. A. an expanded individual (RCLA.Cni.003), camouflaged with the sand that it is buried in, Tial, Pulau Ambon, Indonesia. Photograph by NWL Yap. B. a partially contracted individual (RCLA.Cni.003) extending from a rocky crevice, with sand grains and shell fragments still densely attached to distalmost end, at Tial, Pulau Ambon, Indonesia. Photograph by NWL Yap. C. an expanded smaller individual with tentacles extended, encountered in a bed of Zoanthus at Pulau Tekukor, Singapore, in situ. Photograph by KS Loh, with permission. D. a population of densely packed clustering individuals (ZRC.CNI.1207), encountered in a Halophila ovalis meadow at Cyrene Reef, Singapore. Photograph by NWL Yap. Abbreviation: z, Zoanthus sp. Scale bar = 5 mm.
Cross sections of Heteranthus verruculatus, through the level below actinopharynx, internal morphology. A. mesenteries of holotype Heteranthus insignis (nrs 4076) [= H. verruculatus]. Note complete mesenteries have humps along its edges. B. asymmetrical arrangement of mesenteries in a clustering individual (ZRC.CNI.1207), directives are absent. C. gametogenic tissues with oocytes present on both complete and incomplete mesenteries of an individual (WAMZ33604). Circles indicate the presence of the parietobasilar muscles as pennons. Abbreviation: o, oocytes. Scale = 2 mm. Photographs by NWL Yap.
Pairwise genetic distance range among the taxa for the four molecular markers targeted in this study
Species boundaries delineating tropical sea anemones (Cnidaria, Actiniaria) of the zooxanthellate genus, Heteranthus Klunzinger, 1877, are unclear. There are currently two valid Heteranthus species: type species Heteranthus verruculatus Klunzinger, 1877, first reported from Koseir, Egypt, and H. insignis Carlgren, 1943, from Poulo Condore, Vietnam. In describing the latter from a single, poorly preserved specimen, zoologist Oskar Carlgren expressed apprehension with traits he had used to establish this species. Carlgren’s doubts persisted later in writing when he found a similar-looking sea anemone from the Great Barrier Reef. Crucial details to positively identify either species have since remained limited. Here, we re-diagnosed Heteranthus and re-described its type species based on observations of specimens we have obtained from Singapore and Pulau Ambon (Indonesia), and of museum material collected elsewhere across the Indo-West Pacific region (n > 180). Supported by molecular phylogenetic evidence, the family Heteranthidae Carlgren, 1900 was reinstated and re-diagnosed. Heteranthus verruculatus is encountered in the lower intertidal region amongst seagrass, in rocky crevices, or coral rubble. It occurs as solitary individuals or in clonal clusters, well-camouflaged against the substratum. Individuals were observed to frequently propagate by longitudinal fission, resulting in a varied appearance. Type material of H. verruculatus and H. insignis were re-examined and as we found no differences between them, the two were synonymised. We inferred that Carlgren probably misinterpreted cnidae and histological data in defining H. insignis as a distinct species. This revision clarifies the taxonomy and geographic range of H. verruculatus , an Indo-West Pacific species that is found from the Red Sea to subtropical Australia and Hawaii.
Dendronotus velifer, two historical specimens from the Gullmar Fjord. a-c: habit of specimen 26 mm in length (GNM 3026); f-h: habit of specimen 13.5 mm in length, dorsal, ventral and lateral views respectively (GNM 3027); . d-e: radula of specimen GNM 3026; i-k: radula of specimen GNM 3027, central and lateral teeth respectively; l, jaw; n, o: lectotype, Barents Sea, Vadsø, NHM-UIO nr. 16174. m: genital openings and copulative apparatus. Scale bars: d, i: 100 µm; e, j, k: 30 µm; n, o: 5 mm. Photographs by Tatiana Korshunova (a-h, m) and Karsten Sund (n, o).
Recently collected Dendronotus velifer specimens from the Arctic, which were utilised for the molecular study. a-b: specimen 49 mm in length (preserved), Laptev Sea (ZMMU Op-546), dorsal and lateral views; h-j: specimen 23 mm in length preserved, Kara Sea (ZMMU Op-348), dorsal, lateral and ventral views respectively. c-g: internal characters of the specimen in a-b: radula, central and lateral teeth, and lateral teeth only respectively; n: jaw 9.6 mm in length; k-m: internal characters of the specimen in h-j: radula, central and lateral teeth and lateral teeth only, respectively. Scale bars: c, d, e, g, k: 100 μm; f: 50 μm; l: 20 μm; m: 10 μm. Photographs of specimens (a, b, h-j) by O. Zimina.
Dendronotus robustus specimens from the Arctic, which were utilised for the molecular study. a, b: habit of living D. robustus 35 mm in length, Barents Sea, dorsal and lateral views respectively (ZMMU Op-343); d, e: habit of living D. robustus 19 mm in length (ZMMU Op-344), Barents Sea, dorsal and ventral views, respectively; c: internal characters of Arctic D. robustus specimen ZMMU Op-343: radula of specimen ZMMU Op-344, central and lateral teeth; f-g: radula of specimen ZMMU Op-344, central and lateral teeth respectively; h: jaw of specimen ZMMU Op-343. Scale bars: c: 100 µm; f, g: 30 µm. Photographs by T. Korshunova.
Based on morphological, bathymetric and molecular data comparing recently collected Arctic and North Atlantic specimens with morphological and bathymetrical data on historical museum specimens, a unique relict population of the deep-water mollusc Dendronotus velifer G.O. Sars, 1878 (Gastropoda: Nudibranchia) is shown to have existed in the deepest section of the Swedish Gullmar Fjord (the only true silled fjord in Sweden) at least until the middle of the 20th century. This population is more than 1500 km away from the nearest point in the species' distributional range in the Arctic Ocean today. Using an integrative approach incorporating the data mentioned above, including genetic distances, from recently collected specimens taken from the Arctic Ocean, D. velifer is validated and its species status is restored, for the first time in more than a century after being regarded as a junior synonym of D. robustus. The bathymetric data for historical and recently collected specimens of D. velifer demonstrate significant differences compared to the shallow-water species D. robustus. The findings support the necessity of a stronger protection for the unique marine habitats of the Gullmar Fjord.
Sponges from the Kara Sea (Arctic Russia) collected by the Dutch Polar Expedition 1882-83 are identified and discussed. The expedition experienced an unfortunate course of events, as the research vessel RV ’Varna’ was ice-bound and eventually got crushed by ice, leaving the crew and the scientists stranded on an ice floe drifting around in the Kara Sea. The scientists still managed to do many observations and made collections of bottom animals lowering collecting gear through a hole in the ice. After being enclosed for more than a year in the ice, the men travelled in small boats and sledges to the mainland of Russia and from there returned home. The zoological collections were brought to Copenhagen by the Danish research vessel RV ‘Dijmphna’, from where the material was picked up by the Dutch scientists. Most animal groups were subsequently discussed in a series of papers published in the Bijdragen tot de Dierkunde volume 14 (1887). The sponges of the Dutch Polar Expedition were in a rather bad condition when they arrived in Amsterdam and possibly for that reason were largely ignored. They nevertheless appear to be interesting and are here presented as a belated contribution to the 1887 issue, including the description of a species new to science, Lycopodina ruijsi sp. nov. The results are discussed in the framework of our present knowledge of the sponge fauna of the Kara Sea. In Appendix ten already known species are briefly described and SEM images of their spicules provided as a contribution to Kara Sea sponge morphology
The systematics of pyrgomatids, stemming from the early 1800's, has traditionally been based on the number of plates making up the wall (six, four or one) and specializations in the opercular plates. A recent study of the related bryozobiines focused attention on detailed structural modifications of the basis, which we now find also applies to some highly derived pyrgomatids and an archaeobalanine. Reexamination of the Indonesian coral barnacle Pyrgoma kuri Hoek, 1913 has revealed previously unknown morphological features, including separable opercular plates, a true tergal spur, and a basis lined with ladder to arch-like calcareous structures covering "atrial passageways". Thus, the present study expands our knowledge of such specializations and our understanding of the evolution and relationships of the derived pyrgomatids as well as the archaeobalanines and bryozobiines. The complex modifications of the basis found in these three groups evidently function as an avenue for chemical mediation of growth between the barnacle and its host. Although monophyly of the archaeobalanines and bryozobiines based on such structures is possible, there is no obvious connection between them and the few derived pyrgomatids in which these features occur. There is apparently a propensity toward such modifications in archaeobalanids resulting in parallel evolution in association with distinctly different hosts (e.g., sponges, corals and bryozoans).
A cladistic study was carried out on known species of the characteristically Antarctic genus Oswaldella, adopting as outgroups some other genera included in the family Kirchenpaueriidae. The analysis resulted in a cladogram with low CI in which no relationship between genera can be depicted. However, the hypothesis of monophyly of the genus Oswaldella is corroborated, being supported in our cladogram by five synapomorphies (although all are homoplastic with other taxa or reversed within the species of the genus). The basal relationships of the genus are uncertain, but three species groups are distinguishable within Oswaldella: 1) the O. incognita group, 2) the O. antarctica group, and 3) a clade formed by (O. garciacarrascosai, O. elongata (O. blanconae (O. gracilis (O. herwigi, Oswaldella sp. two)))).
Periclimenes rathbunae Schmitt, 1924 is a western Atlantic symbiotic shrimp species mainly associating with anemones. Adult shrimps of P. rathbunae are characterised by an orange-white spotted colour pattern. During fieldwork along the coast of Curacao (2013), morphologically similar, though generally smaller sized shrimps were collected from the stony coral Dendrogyra cylindrus Ehrenberg, 1834. These specimens were overall more translucent. This study elucidates the taxonomic status of the coral-associated specimens in relation to anemone-associated specimens of P. rathbunae and related anemone-associated species using one nuclear (histone H3, H3), a mitochondrial protein-coding (cytochrome oxidase subunit I, COI) and a mitochondrial ribosomal RNA (16S) gene. Molecular phylogenetic reconstructions clustered the coral-associated specimens with anemone-associated P. rathbunae within a distinct clade, revealing that the aberrant coral-associated shrimp specimens belong to P. rathbunae. It can be concluded that 1) the stony coral D. cylindrus is a host of P. rathbunae, constituting the first record of an association between a scleractinian coral and a palaemonid shrimp species in the Atlantic Ocean; 2) the colour pattern of P. rathbunae is a phenotypically plastic characteristic that varies with size and is depending on the host species; and 3) mean body size of P. rathbunae is smaller on D. cylindrus than on the anemone Stichodactyla helianthus. This raises interesting questions about patterns of host use for this species and warrants further in-depth field ecological study for this species.
Changes in the developing eggs of the potamid freshwater crab, Sinopotamon yangtsekiense from China. A-B) after 13 days; C-E) after 19 days; F) after 65 days. Yo = yolk; Sa = inner membrane a fluid-filled sac; Em = developing embryo; Me = outer membrane; Ce = compound eye of developing crab. Scale bar = 1 mm.  
This paper focuses on the developmental changes that take place inside the eggs of the semi-terrestrial freshwater crab, Sinopotamon yangtsekiense, from Qiantang River in Zhejiang Province, China. The egg consists of two layers, a thick outer membrane and a thin inner membrane that encloses the fluidfilled embryonic sac. Development in this species took up to 77 days, after which the free-living juvenile hatchling crab emerged from the egg. During development the embryo underwent a series of morphological changes that corresponded to the free-living larval stages of marine crabs, and the yolk mass decreased in size and changed color (from creamy pale yellow, to orange, and finally grey). The eggs remained attached to the pleopods in the female's abdominal brood pouch during development and showed a great deal of independence from water. Embryos developed normally whether they were immersed in water or in air. The implications of this adaptation for freshwater crab evolution are discussed.
New material forces a reconsideration of Austromunida casadioi Schweitzer & Feldmann, 2000. Originally the type species of a new genus, we find that this is only a species of the genus Munida Leach, 1820.
In this paper, we revise the Merodon aberrans species group of the genus Merodon Meigen, 1803 (Diptera: Syrphidae), providing morphological diagnoses and descriptions, molecular data for three species, as well as an illustrated key and a discussion of the different taxonomic characters used. We also discuss distribution patterns for this species group. The results revealed that the M. aberrans group is composed of five described species ( M. aberrans Egger, 1860, M. brevis Paramonov, 1926, M. flavitibius Paramonov, 1926, M. hamifer Sack, 1913, and M. warnckei Hurkmans, 1993) and three new ones, namely M. hermonensis Vujić, Radenković et Likov sp. nov., M. petiolatus Vujić, Radenković et Rojo sp. nov., and M. retectus Vujić, Radenković et Likov sp. nov. Following a detailed study of the type material in different entomological collections, the status of several species is revised, one new synonym is proposed (subspecies M. aberrans isperensis Hurkmans, 1993 as junior synonym of M. flavitibius ), lectotypes are designated for M. kneri Mik, 1867 and M. flavitibius , and paralectotypes are designated for M. hamifer and M. flavitibius . Seven out of eight species from the M. aberrans group are distributed in the Asian continent, namely all Caucasian countries, Turkey and Iran, confirming the notion about high diversity of Merodon species in these regions, but also highlighting the need for a systematic faunistic research.
Zebrus pallaoroi sp. nov. nmp P6V 144300, paratype, male, 27.72 + 6.83 mm, Kostanjica, Boka Kotorska, Adriatic Sea, Montenegro: (A) posterior and anterior nostrils; (B) pelvic fin with anterior membrane; (C) ventrolateral head ridges marked with black arrows and transversal connection marked with a grey arrow, small mental fold visible at the lower lip, anteriorly from the transversal connection of ventrolateral ridges. Zebrus zebrus: nmp P6V 142593, male, 21.84 + 5.6 mm, Selce, Kvarner area, Croatia: (D) posterior and anterior nostrils; (E) pelvic fin with anterior membrane; (F) ventrolateral head ridges marked with black arrows. photos by m. kovačić.
Zebrus pallaoroi sp. nov. nmp P6V 144302, holotype, male, 31.81 + 8.51 mm, Kostanjica, Boka Kotorska, Adriatic Sea, Montenegro: head lateral line sensory papillae and canal pores. drawing by m. kovačić.
Bayesian 50% majority-rule consensus tree estimation of phylogenetic relationships of analysed species from the Gobius-lineage sensu Agorreta et al. (2013) based on the mitochondrial gene cytochrome b. Numbers on branches are Bayesian posterior probabilities and maximum likelihood bootstrap values, respectively. Only values higher than 0.9 for posterior probability and 70% for bootstrap are shown.
Bayesian 50% majority-rule consensus tree estimation of phylogenetic relationships of analysed species from the Gobius-lineage sensu Agorreta et al. (2013) based on the nuclear gene rhodopsin. Numbers on branches are Bayesian posterior probabilities and maximum likelihood bootstrap values, respectively. Only values higher than 0.9 for posterior probability and 70% for bootstrap are shown.
The gobies (Gobiidae) are the most diverse fish family in the Mediterranean Sea. Nevertheless, knowledge on their diversity, taxonomy, and phylogenetic relationships is still inadequate. The phylogenetic analyses reveal two genetically highly distinct clades among specimens identified as Zebrus zebrus . A new species, Zebrus pallaoroi sp. nov., is described based on an integrative approach. The neotype of Zebrus zebrus is designated. Genetic data confirm a pronounced level of divergence between Z. pallaoroi and Z. zebrus , with the mean genetic distance on cytochrome b being 18.1% and 1.07% on rhodopsin. Phylogenetic relationships within the Gobius -lineage were estimated on both markers. Morphologically, Z. pallaoroi is distinguished from the only congener Z. zebrus by having a snout longer than its eye, posterior nostril about 4/5–9/10 of the anterior nostril, eye diameter 4.3−4.7 in head length, ventrolateral head ridges transversally connected on the anterior side by a short transversal ridge, anterior membrane midline depth about 2/3 of the spinous ray, head canal pore α diameter about half of the distance between pore ρ and ρ 1 , suborbital sensory papillae row 5i going downwards to or near the level of row d , the distance between row 5i and row d absent or much smaller than the length of row 5i , and the body with ten to eleven vertical dark brown bands. Zebrus pallaoroi was recorded from the southern Adriatic, northern Ionian, and northern and western Aegean Seas, and is a cryptobenthic fish from very shallow waters.
Carcinization, or the process of becoming a crab, has been, and continues to be, a focal point of anomuran evolutionary hypotheses. Traditional examples of carcinization in the Anomura are most celebrated among hermit crabs but certainly are not limited to this group. Carcinization, if it has occurred, has done so independently in all major anomuran taxa. In this critique, the traditional examples of carcinization in the Anomura are reviewed and more modern variations on the theme assessed. Potential pathways of carcinization are examined from perspectives of adult morphology in the Paguroidea, Galatheoidea, Hippoidea and Lomoidea, with emphasis on the Paguroidea. Specific attention is given to the theoretical transformation of a hermit crab-like body form into a “king crab”- like lithodid crab. Resulting coercive evidence indicates: (1) that while the evolution of a crab-like body form certainly occurs, the traditional applications, based on inadequate and often inaccurate data, are flawed; and (2) that lithodid crabs did not arise from a hermit crab predecessor through the process of carcinization.
Isotopic niches represented by Standard ellipse area corrected for small sample size (seac) of the land snail species collected in four study sites (A, B, C, D) at least in five individuals per site.
Variation in seac of land snail species from the four studied assemblages in relation to their lifestyle (a) and body size (b). Variation in percentages of overlapping seac for pairwise species combinations are compared between study sites (c) and three types of lifestyle (d). Different letters refer to significant differences at p < 0.05, tested by gee (a, b) and glm-qp (c, d). The central line of each box refers to the median value, box height to the interquartile range, whiskers to the non-outlier range (i.e., 1.5 times the interquartile range at each side), and small circles to outliers.
Land snails represent a large diversity of species in the forest floor. Some species prefer to stay in the leaf litter, while others like to climb up vegetation. They are considered generalist herbivores/decomposers. Although the exact trophic position of most species is often difficult to determine, a low rate of trophic niche partitioning within an assemblage is assumed. We compared isotopic niche sizes and overlaps between and within four local land snail assemblages using stable isotope Bayesian ellipses. We found significant differences in trophic niche size (expressed by corrected standard ellipse area) as a function of body size and lifestyle. We hypothesised that the larger niche size of smaller and/or arboreal snail species is due to their limited mobility and the presence of spatially structured food resources. In contrast, a broad and similar mixture of leaf litter sources results in a homogeneous diet for individuals of larger, highly mobile, epigean species, i.e., smaller niche size. We documented multiple overlaps of isotopic niches between species within an assemblage, although arboreal species exhibited slightly different niche positions, indicating specific diets. When comparing all pairwise combinations, we found that isotopic niches of species using different lifestyle did not overlap, in contrast to species using similar lifestyle. In addition, the trophic niches of opportunists with respect to lifestyle were intermediate between those of species from the outermost categories. Our results fit the general concept of variable and overlapping trophic niches in co-occurring snail species. However, we were able to demonstrate differences in species that rarely occupy the same microhabitat.
A recent collection of freshwater potamonautid crabs from a newly-explored cave in Ethiopia included a new species of Potamonautes MacLeay, 1838, which is described. The new species is associated with caves but is not troglobitic because it has no special morphological adaptations for life in caves typical of other species of cave-dwelling freshwater crabs. The taxonomic status and biogeographic affinities of other Ethiopian freshwater crab species are discussed. Potamonautes antheus (Colosi, 1920) and P. ignestii (Parisi, 1923) are recognized as valid species, and a key to the species of the country is included. The addition of P. kundudo sp. nov. and the recognition of two previously suppressed taxa raises to six the number of freshwater crab taxa known to occur in Ethiopia.
Results of the identity test. Red and blue arrows show the true calculated niche overlap results. Columns represent the amount of niche overlap in the replicates of the identity tests. The true calculated overlap values (I and D) are far outside the 99.9% confidence intervals of the identity test results and thus highly significant (indicated by two asterisks**).
A) Geographical distribution of haplotypes based on clades. B) Geographical distribution of haplotypes based on haplotypes diversity in PopART 1.7.
A) Zoogeographical classifications of the white wagtail complex and the time of expansion. B) The time-events curve (including dispersal, vicariance, extinction event and the total number of biogeographic events).
Ancestral area reconstruction based on three historical biogeography analyses.
The white wagtail ( Motacilla alba ) species complex with its distinctive plumage in separate geographical areas can serve as a model to test evolutionary hypotheses. Its extensive variety in plumage, despite the genetic similarity between taxa, and the evolutionary events connected to this variety are poorly understood. Therefore we sampled in the breeding range of the white wagtail: 338 individuals were analyzed from 74 areas in the Palearctic and Mediterranean. We studied the white wagtail complex based on two mitochondrial DNA markers to make inferences about the evolutionary history. Our phylogenetic trees highlight mtDNA sequences (ND2, CR), and one nuclear marker (CHD1Z), which partly correspond to earlier described clades: the northern Palearctic (clade N); eastern and central Asia (clade SE); south-western Asia west to the British Isles (clade SW); and Morocco (clade M). The divergence of all clades occurred during the Pleistocene. We also used ecological niche modelling for three genetic lineages (excluding clade M); results showed congruence between niche and phylogenetic divergence in these clades. The results of the white wagtail ancestral area reconstruction showed the influence of dispersal on the distribution and divergence of this complex species. The most important vicariance event for the white wagtail complex may have been caused by the Gobi and Taklamakan deserts. We conclude that the ancestral area of the white wagtail complex was probably in the Mediterranean, with its geography having a considerable effect on speciation processes.
Body of an adult male of S. graffii: ventral and dorsal (A) view, with aedeagus partly everted; head in microscopic slide (B) with reduced mouthparts and their close-up in macroscopic view (C).
Cross sections of adult males of S. graffii (A, C) and S. quercus (B, D) showing the total body sections (A, B) and section through head and prothorax (C, D).
Details of the nervous (A, B) and reproductive (C, D) systems of adult male of S. graffii (A, B), 2nd instar larva of S. graffii (C) and adult male of S. quercus (D).
Features of males and of the alimentary tract of Lachninae aphids compared to other Aphidomorpha; phylogeny of Lachninae after Chen et al. (2016).
Dwarfish males are a relatively common phenomenon in animals, occurring in various taxa, most often when females conduct a sedentary life mode. Such males, beside smaller size, exhibit a series of morphological and anatomical alterations, mostly structural reductions. Here we present the case of the alimentary tract of dwarfish males of the aphid genus Stomaphis where, despite it being structurally normal, it does not serve its original function due to a lack of mouthparts. Cross-sections through mounted specimens revealed also that nervous and reproductive systems are fully developed. The question arises as to whether such a system may be considered vestigial, or an exaptation with secondary function shifted to play new primary function. Because the aphid genus Stomaphis is known from the fossil record to have existed for at least ca. 14 My and all of its species have dwarfish, arostral males, this indicates that it may be too short a period for reduction of the whole system. It also raises questions about the mechanisms of loss of the primary functionality of the whole physiological unit, and the influence of such modification on the evolution of its phylogenetic successors. Secondary functions of the tract are speculated to be responsible for its endurance.
The stygofaunal family of Bathynellidae, is an excellent group to study the processes that shape diversity and distribution, since they have unknown surface or marine relatives, high level of endemism, and limited dispersal abilities. Recent research on Bathynellidae in Western Australia (Pilbara) has uncovered new taxa with unexpected distributions and phylogenetic relationships, but the biogeographical processes that drive their diversification on the continent are still unclear. By exploring the diversity, distribution, and divergence time of Bathynellidae in a setting such as the perched and isolated aquifers of the Cleaverville Formation in the north of the De Grey River catchment (Pilbara), we aim to test the hypothesis that vicariance has shaped the distribution of this family, specifically if one or multiple vicariant events were involved. We analysed the specimens collected from perched water in different plateaus of the Cleaverville Formation, combining morphological and molecular data from mitochondrial and nuclear genes. We described two new species and genera ( Anguillanella callawaensis gen. et sp. nov. and Muccanella cundalinensis gen. et sp. nov.), and two additional taxa are recognised using morphology and/or Automatic Barcode Gap Discovery and Poisson Tree Processes species delimitation methods. New genera and species result restricted to isolate perched aquifers on single plateaus and their distributions, phylogenetic relationships, and divergence time estimates support multiple vicariant events and ancient allopatric speciation.
Life cycle of A. corruptrix (Schlechtendal, 1870) is treated and corrections to previous experiments are discussed. A new sexual form for A. corruptrix is herein described, while A corruptrix forma larshemi is considered a valid species and for taxonomical reasons is renamed as Andricus improprius n. stat & n.sp, only known by the sexual form, and not linked with A. corruptrix. Lectotypes for A. improprius n. stat & n. sp. (= A. larshemi not available) are also designated.
The biogeography and genetic structure of aquatic zooplankton populations remains understudied in the Eastern Palearctic, especially the Qinghai-Tibetan Plateau. Here, we explored the population-genetic diversity and structure of the cladoceran waterflea Daphnia magna found in eight (out of 303 investigated) waterbodies across China. The three Tibetan D. magna populations were detected within a small geographical area, suggesting these populations have expanded from refugia. We detected two divergent mitochondrial lineages of D. magna in China: one was restricted to the Qinghai-Tibetan Plateau and the other was present in lowland China. Several different haplotypes in the Qinghai-Tibetan Plateau were most similar to those from various parts of Siberia, suggesting that as a source region. We also found substantial genetic differentiation between D. magna populations from the Qinghai-Tibetan Plateau and those from lowland China. Moreover, significant morphological differences were identified: D. magna from the Qinghai-Tibetan Plateau had a larger head length, body length and body width than did those from lowland China. Geographical and environmental factors were correlated with the observed morphological variation and genetic divergence of D. magna in China. Our data offer an insight into the divergence of freshwater zooplankton due to the uplift of the Qinghai-Tibetan Plateau.
Fossil decapods of the Lower Triassic marine strata of Madagascar are reviewed. These display affiliation to the dendrobranchiates. These include Antrimpos madagascariensis , two species of Ifasya ( I. madagascariensis and I. straeleni ) and Ambilobeia karojoi .
Members of the strictly stygobiont, continental subterranean amphipod family Metacrangonyctidae are reported for the first time outside the Old World. Two new species of Metacrangonyx are described from two widely separated localities in the Dominican Republic (Hispaniola), one facing the Caribbean and the other the Atlantic ocean. The discovery of metacrangonyctids in the western Atlantic suggests that they are an ancient subterranean lineage tied to the shores of the Tethys belt, and thus weakens previous biogeographic arguments raised to favour their separate and independent family status with respect to the Hadziidae. The discovery in the Mediterranean of marine populations of metacrangonyctids is reported as well, and both findings are used to test the reliability of the scenario currently held for the origin and evolution of this peculiar group of stygobiont amphipods. It is concluded that Metacrangonyx is a thalassoid lineage already present in the shores of the western Tethys before the complete aperture of the central North Atlantic (circa 110 Myr BP), and with marine populations persisting at both shores of this ocean until some time in the Quaternary, in case they have not yet disappeared. Evidence derived from Hispaniolan and Balearic Metacrangonyx does not support the correspondence between species-groups and the time at which precise waves of colonization of continental ground waters took place (after Turonian and Senonian marine regressions, respectively) as is assumed to occur for Old World taxa.
Knowledge about the development of the nervous system in cirripeds is limited, particularly with regard to the changes that take place during the two metamorphoses their larvae undergo. This study delivers the first detailed description of the development of the nervous system in a cirriped species, Amphibalanus improvisus by using immunohistochemical labeling against acetylated alpha-tubulin, and confocal laser scanning microscopy. The development of the nervous system in the naupliar stages corresponds largely to that in other crustaceans. As development progresses, the protocerebral sensory organs differentiate and the intersegmental nerves forming the complex peripheral nervous system appear, innervating the sensory structures of the cephalic shield. During metamorphosis into a cypris the lateral sides of the cephalic shield fold down into a bilateral carapace, which leads to a reorganization of the peripheral nervous system. The syncerebrum of the cypris exhibits the highest degree of complexity of all developmental stages, innervating the frontal filaments, nauplius eye, compound eyes and the antennules. During settlement, when the second metamorphosis occur, the closely associated frontal filaments and compound eyes are shed together with the cuticle of the carapace and the antennules. In adults, the syncerebral structures are reduced while the ventral nerve cord and the peripheral nervous system increase in complexity. The peripheral nervous system plays an important role in processing sensory input and also in settlement. In summary, through the larval development we observed a structural and thus also functional increase of complexity in favor of the peripheral nervous system and the ventral nerve cord.
Mantellid frogs present an extensive adaptive radiation endemic to Madagascar and Comoros, being the subfamily Mantellinae the most morphologically and ecologically diverse. The Mantellinae present key innovative evolutionary traits linked to their unique reproductive behavior, including the presence of femoral glands and a derived vomeronasal organ. In addition, previous studies pointed to size differentiation in playing an important role in species’ dispersal capacities and shaping of their geographic ranges. Despite the high phenotypic variation observed in this clade, to date an exhaustive morphological analysis of their anatomy has still not been performed, much less in relation to internal structures. Here, we present a comprehensive skeletal description of a mantellid species, Blommersia transmarina , from the island of Mayotte in the Indian Ocean, which has potentially undergone a process of moderate gigantism compared to other Blommersia species. We describe its intraspecific skeletal variation utilizing non-destructive volume renderings from μCT-scans, and characterize the presence of sexual dimorphism and size covariation in skeletal structures. Notably, we found numerous signs of hyperossification, a novel structure for mantellids: the clavicular process, and the presence of several appendicular sesamoids. Our findings suggest that skeletal phenotypic variation in this genus may be linked to biomechanical function for reproduction and locomotion.
Internal structure of a Dyopedos bispinis mast including diatoms and multicellular algae. А -drawing of a semi-thin mast crosssection; B -enlarged detail of A, LM micrograph; C and D -LM micrographs of semi-thin sections illustrating algae included in the central mast cylinder; E and F -SEM micrographs of mast surface showing the diatom Thalassionema nitzschioides; G -SEM micrograph of the inside of the mast laminated cortex showing the presence of numerous pelagic and benthic diatoms. Arrowheads -mucous pads connecting T. nitzschioides cells; as -silk threads; bda -likely benthic diatoms; C -central cylinder of the mast; da -diatoms; ma -multicellular algae; P -laminated cortex of the mast; pda -likely pelagic diatoms; Tn -diatom Thalassionema nitzschioides.
Ultrastructure of Dyopedos bispinis mast surface. А, B, C and D -SEM micrographs of the mast surface near the distal tip (A) and other parts of the mast (B, C and D) showing that silk threads were thinner near the mast tip (arrows, A) than elsewhere (arrowheads, B and C), that threads of varying widths are sometimes presented (t1 and t2, D), that detritus can be visible through the silk layer (B) or not (C) and that regular parallel silk threads are sometimes observable (black and white arrowheads, B and C); E -transmission electron microscopy (TEM) micrograph of an ultra-thin mast cross section showing numerous amphipod silk layers (L1-L6) on the mast surface. Abbreviations: arrows -thin threads; arrowheads -regular parallel thick silk threads; С -central cylinder in mast cross-section; L1-L6 -layers of silk threads (L1 and L3 -threads, likely lying perpendicular to the mast axis; other -at an angle); P -mast cortex in cross section; t1 and t2 -threads of varying widths.
Dyopedos bispinis pereopodal silk-producing glands, schematic reconstructions from serial sagittal, semi-thin sections. A -Distribution of glands in female Dyopedos bispinis 3-d or 4-th pereopod, showing two gland groups, proximal (D1) and distal (D2), and their ducts falling into a common chamber in the tip of the leg; B -duct system of the D1 glands in the basis of pereopods 3 or 4, female. Abbreviations: arrow -common opening of all pereopodal glands; arrowhead -point of coalescence of two D1 main ducts; Ch -dactylar chamber; D1 -proximal glands (D1); D2 -distal glands (D2); DB -duct bundle; LD -lateral duct of D1 gland; m -pereopodal muscles; MD -main duct of D1 gland. Arabic numerals -number of pereopod segments; 2 -basis; 3 -ischium; 4 -merus; 5 -carpus; 6 -propodus; 7 -dactylus.
Cellular membrane invaginations in D1 secretory cells. A and B -schematic representations of two consecutive serial ultra-thin sections (with a 3-5-µm interval) through the D1 gland, showing that the invaginations (i) are likely flat and perpendicular to the section plane; C -TEM micrograph illustrating deep secretory cell invaginations filled with lining cell extensions; D -TEM micrograph of the widening at the tip of an invagination; E and F -TEM micrographs showing different forms of lining represented as multiple overlapping cytoplasmic extensions (E) or as a continuous cytoplasmic layer (F). Abbreviations: arrowheads -overlapping lining cytoplasmic extensions; as -accumulation site; c -cuticle; er -endoplasmic reticulum; h -haemocoel; hyp -hypoderm; i -cellular membrane invaginations of secretory cells; LC -lining cell; mt -mitochondria; nu -nucelus of secretory cell; SC, SC-1 and SC-2 -secretory cells; sgsecretory granules; ? -fragments of tissue damaged during fixation or embedding.
Comparative schematic drawings of Dyopedos bispinis proximal glands (D1) and other crustacean tegumental glands. A, B and C -several types of crustacean tegumental glands modified from Talbot and Demers, 1993 and Rieder, 1977: A -bicellular glands, B -tricellular glands, C -rosette glands; D, E and F -pseudotubular silk glands of Amphipoda: D -A. rubricata (after Neretin, 2016), E -J. falcata (modified from Nebeski, 1880), F -Dyopedos bispinis; G and H -tube-building glands of the tanaid H. oerstedii (Kroyer 1842) (after Blanc, 1884), also likely pseudotubular; I -cirripedian cement glands (modified from Lacombe and Liguori, 1969). Abbreviations: as -accumulation site; c -cuticle; CC -central cell; DC -duct cell; hyp -hypoderm; IC -intermediary cell; LD -lateral duct; MD -main duct; nu, nu1 and nu2 -nucleuses of secretory cells; SC -secretory cell; ySC -young secretory cells.
In the present study, we investigated the biology of Dyopedos bispinis, a mast-building amphipod that is abundant near the N. Pertsov White Sea Biological Station. To examine the peculiarities of mast building in Dyopedos bispinis, we studied the social structure of individuals inhabiting the masts and identified the preferred substrata through underwater photography and direct observations, characterized the internal and external structures of the masts, and studied the ultrastructure of pereopodal silk glands using scanning and transmission electron microscopy (SEM and TEM, respectively). The most frequent substrata for mast building are other fouling organisms, including hydroids, bryozoans, ascidians and sponges. As in other corophiids, each Dyopedos bispinis mast represents the territory of one female and, occasionally, one male, but unique collective masts occupied by three or more (up to 23) adults were also observed. Masts comprise one or 2-4 central cylinders and a laminated cortex that contains detritus and amphipod silk layers. The pereopodal glandular complex of Dyopedos bispinis is composed of two distinct gland groups, proximal and distal, in each pereopod 3-4, and ducts in the glandular complex lead into a common chamber in the dactylus. The proximal glands are multicellular; their secretory cells are uninuclear, unlike in certain other amphipods; and the cell membrane is deeply invaginated. The invaginations are filled with extensions of the cytoplasm of lining cells, but the origin of the lining is unclear. Axon terminals were observed adjacent to the secretory cells, and it is assumed that these axons regulate amphipod silk glands. The proximal silk glands of Dyopedos bispinis have similarities with the lobed and rosette glands of isopods, but they have strongly elongated forms. We refer to these glands as pseudotubular glands. Such glands are rarely observed in Crustacea and have only been described in silk-producing pereopodal systems of marine Peracarida and in the antenna of terrestrial Malacostraca.
Investigations of amphipod embryonic development have a long tradition. However, many aspects of amphipod embryology are still controversial. These concern, among others, the nature of the cleavage, the origin of the germ disc, and the mode of gastrulation. On the other hand, amphipods show the same characteristic type of invariant cell division pattern in the germ band as other malacostracans. Since amphipods seem to undergo a stereotyped pattern of early cleavage they are highly interesting for our understanding of the evolution of arthropod development. In this paper, we describe the cleavage pattern of the amphipod crustacean Orchestia cavimana from the zygote to gastrulation and the formation of the germ disc using direct observation, scanning electron microscopy, histology, video recording, and lineage tracing with a vital dye. The early development follows the mode of a total, radial, unequal cleavage with a determinate stereotyped pattern. A small transient blastocoel is formed. The 8-cell stage is characterised by 4 micromeres and 4 macromeres. One quadrant is smaller than the others. There are two kinds of eggs that show a mirror handed image. The 16-cell stage is the last regular stage after which the blastomeres divide highly asynchronously. The germ disc is formed by the descendants of the macromeres and some micromere derivatives. The other micromeres constitute the extra-embryonic region. Migration of macromere descendants is involved in germ disc formation accompanied by the extrusion of the yolk. During this process some vitellophages are formed. The gastrulation sensu stricto is initiated by the micromere derivatives of the smallest quadrant at the anterior of the forming germ disc. A true blastopore occurs which involves an invagination and the immigration of cells. Our data help to correct erroneous interpretations of former students of amphipod development. We can show that many characters of amphipod embryonic development are apomorphic supporting amphipod monophyly. With the present investigation we contribute to a complete understanding of the embryonic cell lineage of amphipods from the egg to segment formation and organogenesis.
Morphological disparity within the Hyalella species-flock of Lake Titicaca. A, H. robusta; B, H. longipalma; C, H. montforti; D-E, H. crawfordi; F, H. neveulemairei; G-H, H. armata; I, H. knickerbockeri; J, Hyalella n. sp. 1; K, H. lucifugax. See key to species for description of precise armature arrangement on each species. [A-C, E: after Chevreux (1907); D, E: after Coleman & González (2006); G, H: after González & Coleman (2002); I: modified from Weckel (1910); K: modified from Faxon (1876)]
Bayesian phylogeny and molecular species delimitation of South American Hyalella based on currently available cox1 mitochondrial data (present work and Barcode of Life DATA Systems (BOLD) repository project TTKK). Nodes with maximum nodal support are remarked with circles. Purple dots on branch tips indicate haplotypes exclusively sampled in South America outside the Altiplano area (see supplementary fig S1 for details). See main text for details on molecular species delimitation methods and results.
The Hyalella species diversity in the high-altitude water bodies of the Andean Altiplano is addressed using mitochondrial cox1 sequences and implementing different molecular species delimitation criteria. We have recorded the presence of five major genetic lineages in the Altiplano, of which one seems to be exclusive to Lake Titicaca and nearby areas, whereas the rest occur also in other regions of South America. Eleven out of 36 South American entities diagnosed by molecular delimitation criteria in our study are likely endemic to the Titicaca and neighbouring water bodies. We have detected a remarkable disagreement between morphology and genetic data in the Titicacan Hyalella , with occurrence of several cases of the same morpho-species corresponding to several Molecular Operational Taxonomic Units (MOTUs), some even distantly related, and other instances where a particular MOTU is shared by a morphologically heterogeneous array of species, including species with body smooth and others with body heavily armoured. Species diversification and incongruence between morphological and molecular boundaries within this species assemblage may be associated to the sharp changes in hydrological conditions experienced by the water bodies of the Altiplano in the past, which included dramatic fluctuations in water level and salinity of Lake Titicaca. Such environmental shifts could have triggered rapid morphological changes and ecological differentiation within the Hyalella assemblage, followed by phenotypic convergence among the diverse lineages. Factors such as phenotypic plasticity, incomplete lineage sorting or admixture between divergent lineages might lie also at the root of the morphological-genetic incongruence described herein.
Lake Titicaca, in the High Andes of Perú and Bolivia, harbours the world’s third most speciose ancient-lake amphipod radiation on record. A minimum of nineteen species of Hyalella derived from at least five independent colonization episodes concentrate in this high altitude water body, although the actual species number present has not yet been established and could be much higher. Herein, we take advantage of the description of three new species ( H. krolli, H. gonzalezi , and H. hirsuta ) and the re-description of other two ( H. solida and H. nefrens ) to assess the feasibility of adopting a dna -based identification approach to resolve the magnitude of this highly speciose amphipod assemblage. A Bayesian phylogenetic analysis of the evolutionary relationships among South American Hyalella cox1 haplotypes, including those of four out of the five species dealt with herein, shows a great disagreement between taxonomic units delimited under morphological and genetic data, hampering species identification exclusively based on cox1 dna barcode sequences.
Top-cited authors
Bert W Hoeksema
  • Naturalis Biodiversity Center
Vincent Nijman
  • Oxford Brookes University
Bastian T. Reijnen
  • Naturalis Biodiversity Center
Adriaan Gittenberger
Jan Willem Arntzen
  • Naturalis Biodiversity Center