The dissection of the heads of three adult roe deer (Capreolus capreolus) provided evidence that this species of the Cervidae, like carnivores, lagomorphs and certain members of the Bovidae, possesses a zygomatic salivary gland. Homology of this salivary gland in ruminants and carnivores is assumed on the basis of its over-all topographic position and the number and course of its excretory ducts. The zygomatic gland of roe deer is a polystomatic gland and amounts to 0.02% of body weight. As in Saiga tatarica and Capricornis crispus (Bovidae), its secretions are predominantly serous. Its slightly alterated position in roe deer (and in bovids) seems to be caused by an evolutionary transformation of orbitotemporal proportions and the formation of a lacrimal bulla, in particular. This is an inflation of the intraorbital portion of the lacrimal bone providing ventral support to the ocular bulb. The lacrimal bulla is a late evolved character and emerges late in ontogeny. Its postnatal development in roe deer is presented. Comparison with the neonatal stage of lacrimal morphology in cattle suggests a similar ontogenetic development in the Bovidae. The adult grysbok (Raphicerus melanotis, Neotraginae, Bovidae) provides a ‘model situation’ of the primitive character state at the beginning of the evolutionary development of a lacrimal bulla. Zygomatic gland, lacrimal bulla and other structural elements of the ruminant orbitotemporal region provide an example of the interlocked evolutionary transformation of a complex system, the morphological result of which is a multi-layered compromise between several structurofunctional constraints.
Within the Sabellida, Serpulidae and Sabellidae are sister groups and possess uncini, which are aligned in a transverse row inside the neuropodial rim of the thorax and the notopodial rim of the abdomen. In several sabellid species the shaft (manubrium) of thoracic neurochaetae is much longer than that of abdominal notochaetae. In order to compare both kinds of chaetae and to find hypotheses on the chaetation in the ground pattern of the Sabellidae, structure and development of thoracic and abdominal uncini of the small sabellid Fabricia stellaris were studied ultrastructurally and compared with SEM studies of the sabellids Branchiomma bombyx, Euchone analis and Sabella spallanzani, and the serpulids Protula tubularia and Pomatoceros triqueter. The thoracic uncini of F. stellaris consist of a large rostrum, which is surmounted by several spines of the capitium. Rostrum and capitium are bent towards the manubrium. The chaetae are formed at the dorsal edge of the neuropodial rim, close to the notopodial group of capillary chaetae. A group of microvilli preforms the rostrum, while individual microvilli give rise to each spine of the capitium. During chaetogenesis re-orientation of the microvilli causes curvation of the rostrum and capitial spines. The abdominal uncini have no rostrum. At the begining of their chaetogenesis several individual microvilli form the spines of the capitium. Their characteristic curvature also results from re-orientation of the microvilli during chaetogenesis. A comparison within the Sabellida leads to the assumption that reduction of the rostrum in abdominal uncini occured in the stem lineage of the Fabriciinae, because Sabellinae, Caobangia and Serpulidae retain the plesiomorphic uncinal design with rostrum, capitium and a short manubrium. Increase of the manubrial length of thoracic uncini evolved in the stem lineage of the Sabellidae. This result corroborates the assumption that sabellids evolved an elastic, rapidly secreted tube the animals can easily migrate from and thus were able to colonize instable environments.
The larynges (except for the epiglottis) of two adult Mongolian gazelles, one male and one female, were dissected. This species is characterized by a pronounced sexual dimorphism of the larynx. Dimorphism with regard to the size of the entire larynx and of the thyroid cartilage is about 2:1 whereas the difference of mean body mass is about 1.3:1 between males and females. Unexpectedly, and in contrast to other bovids, the larynx of the male Mongolian gazelle has a paired lateral laryngeal ventricle. However, in contrast to horse, dog, pig and many primate species also possessing such a paired ventricle, its rostral opening in the Mongolian gazelle is situated lateral to the corniculate process of the arytenoid cartilage. The neck of the laryngeal ventricle is embraced by the bifurcated cuneiform process of the epiglottis. Despite the enlarged laryngeal cartilages, the vocal process of the male arytenoid cartilage is relatively shorter than that of the female. The male thyroarytenoid muscle is clearly separated into a rostral ventricular muscle and a caudal vocal muscle whereas the female's, as in other bovids, is almost uniform. The lateral sac of the two-chambered laryngeal ventricle in the male projects laterally between the ventricular and the vocal muscle. As in the domestic bovids and in many other artiodactyls the larynx of the male Mongolian gazelle is lacking any rostrally directed membraneous portion of the vocal fold. Instead, the thick and tough bow-like vocal fold projects caudally into the infraglottic cavity and is supported by a peculiar pan-like fibroelastic pad. This resilient element, situated medial to the bipartite thyroarytenoid muscle, might be a homologue of the vocal ligament, eventually including lateral portions of the elastic cone. A fibroelastic pad is absent in the female. The resilient floor of the laryngeal vestibulum, ventral to the fibroelastic pad, is rostrally and caudally subducted by tube-like spaces. Evolutionary enlargement of the male larynx, including the vocal folds, and of the caudal portions of the vocal tract may have shifted the fundamental and formant frequencies to a lower register. The paired lateral laryngeal ventricle might produce an amplitude increase of the vocalizations assisted by differential action of the bipartite thyroarytenoid muscle. In addition, the peculiar shape, size and tough consistency of the male vocal folds may, as in roaring felids, assist in producing high amplitude and low frequency vocalizations. Perhaps the biological role of the enlarged male larynx of Procapra gutturosa has evolved in relation to its mating system. In the rutting season, dominant males establish individual territories and maintain harems. During prolonged courtship prior to mating, these males perform an acoustic display uttering loud and guttural bellows. In addition, the bulging ventral neck region of males may serve as an optical attractant for the females. Thus, the evolution of the enlarged larynx of the male Mongolian gazelle may have been favoured by sexual selection.
The names Glomeris guttata and G. connexa are each used for at least two different taxa, all of which show a dorsal colour pattern of four rows of light spots on a dark ground. We use allozyme and literature studies to document that the name G. guttata Risso, 1826, can only be applied to a species that is endemic to the Var Valley in Southern France, while G. connexa C. L. Koch, 1847, must be used for the species which has a disjunct distribution in Silesia, Bavaria, Savoy and from the Southern Alps to the Apennines. Based on allozyme data, G. guttata proved to be closely related to G. valesiaca Rothenbühler, 1899, that is distributed from Western Switzerland along the Alps to Provence. G. tetrasticha Brandt, 1833, is the valid name for the species that was erroneously called G. connexa in the literature; G. tetrasticha is distributed from Eastern Europe over Germany to Switzerland. G. connexa C. L. Koch is clearly separated by its colour pattern from the other three taxa. A separate position is also supported by the allozyme data. Furthermore, we show that G. tetrasticha, which is morphologically similar to the northern populations of G. valesiaca, is clearly differentiated from G. valesiaca and from G. guttata according to the genetic data. A key to the identification of the species, distribution maps and figures with specific colour patterns are presented.
The genus Obelus, so far known from shells only, is re-described on the basis of the anatomy of its genital system. Its range is here restricted to north-western Africa and the Canary Islands. Four species are traditionally listed for the Canary Islands: Obelus despreauxii, O. moderatus, O. mirandae and O. cyclodon. The presence of the last species on the Canary Islands is doubtful, whereas the fossil/subfossil presence of O. pumilio is documented. The species Helix morata also belongs to the genus, as well as a new species, O. discogranulatus sp. nov. The genital systems of all confirmed extant Canarian species are shown. Obelus has a peculiar vaginal stimulator appendix (“appendicula”) which is homologous to the penial appendix of the Orthurethra and to the stimulatory organ of other Stylommatophora, with the exception that the A3 portion is missing. The genus is diagnosed by characters of the vaginal stimulator appendix, such as a curved, finger-like A2 portion of the appendicula ending proximally in a blind, well-developed muscular sac, and by the slender tubular A4 portion arising laterally from the muscular sac duct. We conclude that Obelus belongs to the Cochlicella group because it shares an appendicula with the other genera of the group. However, it differs in anatomical details of this structure. The Cochlicella group should be recognized as a separate family Cochlicellidae Schileyko, 1972, with close relationships to the Helicellidae and the Hygromiidae. A new diagnosis for Cochlicellidae is proposed and its phylogenetic relationships are discussed.This is: Notes on the Malacofauna of the Canary Islands, No. 46.
A survey of adult male Mongolian gerbils, Meriones unguiculatus (Milne-Edwards, 1867), either trapped during an expedition in Mongolia near 47 °N and 105,5 °E in June 1995 (WILD) or obtained from a laboratory strain bred in captivity since 1935 (LAB), revealed significant morphological and behavioural differences, which are likely a result of domestication in the laboratory strain. Mean body length (125.4 mm), tail length (95.5 mm) and body weight (53.6 g) was lower in WILD, although no other external characteristics were obviously different. Related allometrically to net carcass weight, organ weights were significantly lower (p < 0.01) in LAB (brain – 17.6%, eyes – 26.0%, heart – 22.3%, lungs – 43.3%). Seizures frequently seen in LAB were absent in WILD trapped (n = 167) or subsequently housed in Germany (n = 81), and rare in their offspring. Mean litter size was greater in LAB (n = 5.5) than in WILD bred in the laboratory (n = 4.4). The WILD breeding strain was named Ugoe:MU95.A genetic bottleneck (n = 9) that occurred in 1954 and remarkably smaller brains in LAB indicate that the laboratory strain has become domesticated and should be designated as “Laboratory gerbils” (M. unguiculatus forma domestica) to signify this new case of domestication among rodents.
Class Bdelloidea of phylum Rotifera comprises aquatic microinvertebrates that are known for both obligate parthenogenesis and for resisting desiccation through a dormant reversible state. In the frame of an investigation about the role of the nervous system in controlling life cycle, reproduction and dormancy, we describe the serotonergic system of a bdelloid, Macrotrachela quadricornifera, using serotonin immunohistochemistry and confocal laser scanning microscopy. Serotonin immunoreactivity is present in the cerebral ganglion, lateral nerve cords and peripheral neurites. The cerebral ganglion consists of perikarya that send neurites cephalically to the rostrum and corona. A pair of neurites exits the cerebral ganglion as lateral nerve cords, and proceeds caudally to the pedal ganglion where additional neurites enter the foot. Based on the location of serotonergic immunoreactivity, we hypothesize that the neurotransmitter is involved in both motor activity (e.g., ciliary beating, inchworm-like locomotion) and sensory activity. A comparison between the serotonergic nervous systems of M. quadricornifera and species of Monogononta reveals differences in the numbers and patterns of cerebral perikarya, peripheral perikarya, and periperhal neurites. These differences may have functional significance for understanding adaptations to specific environments and/or systematic significance for reconstructing the rotiferan ground pattern.
The monogonont rotifer Bryceella stylata was investigated with light, electron and confocal laser scanning (CLSM) microscopy to provide detailed insights into its anatomy and new information for future phylogenetic analyses of the group. Results from CLSM and phalloidin staining revealed a total of six paired longitudinal muscles (musculi longitudinales I–VI) and eight circular muscles (musculi circulares I–VIII) as well a complex network of mostly fine visceral muscles. In comparison with other rotifer species that have been investigated so far, B. stylata shares the presence of the circular and longitudinal muscles: musculus longitudinalis ventralis, musculus longitudinalis lateralis inferior, musculus longitudinalis dorsalis, musculus longitudinalis capitis and musculus circumpedalis. However, the species lacks lateral and dorsolateral longitudinal muscles and some circular muscles (e.g., corona sphincter, musculus pars coronalis). With light and electron microscopy, we were able to document the precise number of pseudosegments and the arrangement of the chambers comprising the trophi elements. Furthermore, our observations revealed several new morphological characteristics, including a shield-like epidermal projection covering the dorsal antenna, an epidermal projection restricting the corona caudally and an unpaired hypopharynx with distinct shovel-like structures.
Aeolosomatidae and Potamodrilidae are small meiofauna annelids of apparently simple organization and uncertain phylogenetic position. Potamodrilidae was regarded either as a subtaxon of Aeolosomatidae, united with them as Aphanoneura, or entirely unrelated to Aeolosomatidae. Moreover, the groups have been placed in various positions within Annelida: as sister group of Clitellata, as a highly derived clitellate taxon, or excluded from Clitellata and not closely related to them due to great morphological differences. Although molecular studies give strong support for the exclusion of these two taxa from Clitellata their questionable sister group relationship to each other has not been addressed specifically. In the present study sequences of the nuclear 18S rDNA and the mitochondrial Cytochrome Oxidase I gene were used for addressing this question. In addition to the available nuclear 18S rDNA sequences, partial sequences of Cytochrome Oxidase I of Rheomorpha neiswestnovae (Lastochkin, 1935) and Potamodrilus fluviatilis Lastochkin, 1935 along with other polychaete taxa were determined. Combined analyses of these two genes were conducted using Maximum Parsimony and Bayesian analysis. A sister group relationship of Aeolosomatidae and Potamodrilidae is significantly supported in all. As in previous studies a relationship to Clitellata is not supported but the phylogenetic position of both Aeolosomatidae and Clitellata within the polychaetes remains enigmatic.
Morphology and systematics of the rotifer genus Pseudoploesoma Myers, 1938 are discussed. The genus is transferred from Synchaetidae to Notommatidae. One species, P. formosum (Myers, 1934), is recognized. Pseudoploesoma greeni Koste, 1978 probably belongs to Notommata but must be considered incertae sedis and species inquirenda on account of its poor description; P. greeni sensu Coussement and Dumont (1980) is identified as Notommata copeus Ehrenberg, 1834. (c) 2007 Elsevier GmbH. All rights reserved.
Courtship, mating and spermatophores of Phrynichus exophthalmus and P. deflersi arabicus nov. ssp. are described. Courtship of P. exophthalmus is more complex than in other amblypygids, with close contact between mates nearly throughout the mating dance. After spermatophore formation, the female is lured to the spermatophore and then firmly pressed onto it. Mating behaviour and spermatophore confirm the placement of this species in the Phrynichus ceylonicus group and show that the similarities with Euphrynichus, like long and thin pedipalps with bacilliform apophyses instead of spines, are the result of convergent evolution. Courtship of P. d. arabicus is conservative, similar to that of P. dhofarensis and many other amblypygids. After spermatophore formation, the female is lured to the spermatophore, then pulled over and pressed onto it. The results suggest that the P. ceylonicus group and the P. deflersi group and sister groups, but the low number of investigated species precludes a definite conclusion.
The freshwater rotifer, Filinia novaezealandiae, is a planktonic species in tropical limnetic ecosystems. Like other species in the genus, F. novaezealandiae has two mobile, anterolateral setae that supposedly facilitate saltation through the water column as a means of escape from predators. However, very little is known about setal structure or the control of setal movement. Here, we use a combination of behavioral observations, scanning and transmission electron microscopy, phalloidin staining of F-actin, conventional fluorescence and confocal laser scanning microscopy, and three-dimensional (3D) analysis software to investigate saltation in F. novaezealandiae and gain insight into the contribution that both setae and muscles play in locomotion. Results from EM reveal that the paired anterolateral setae are smooth, hollow extensions of the syncytial integument and constructed of two layers: a thin internal and thick external lamina. The setal cavity is continuous with the body cavity of the trunk, and the setae articulate with the trunk at a series of flexible folds. A lack of direct muscular supply to the setae indicates that their movement is likely to result from a combination of: (1) contractions of specific muscle sets (e.g., anterior transverse muscle, post coronal ring muscle) that insert on the body wall around the setae; and (2) changes in hydrostatic pressure within the body cavity that accompany coronal withdrawal (via contraction of retractor muscles) and extension. These descriptions, together with behavioral observations, indicate that the primary function of the setae is likely to be predator deterrence and not predator evasion. Likewise, saltation is probably a result of heightened coronal activity that immediately follows cycles of setal abduction/adduction. These insights, together with new descriptions of the muscular system in F. novaezealandiae, may be of utility in understanding the evolution of locomotory mechanisms among rotifers.
Biochemical and ultrastructural advances in the latter part of the 20th C. have revolutionized our understanding of cryptobiosis since Anton van Leeuwenhoek gave the first formal description of the phenomenon at a Royal Society lecture in 1702. Keilin coined the term cryptobiosis in 1959 to describe the entry into a reversible ametabolic state and recognized that such ‘latent life’ could encompass processes induced by dehydration, cooling, and perhaps osmotic stress and anoxia. True cryptobiosis, as now understood, depends on the loss of a liquid water phase and can be induced by desiccation or freezing. Loss of ‘bulk’ or liquid water may result directly from evaporation, or arise through vitrification promoted by the formation of a carbohydrate matrix. The carbohydrates in question appear to be ubiquitous in cryptobiotes and serve multiple additional roles: as compatible intracellular osmolytes during desiccation or freeze-dehydration; as stabilizers of protein quaternary structure and lipid bilayer integrity with declining free water activity; and as supercoolants. Plants tend to rely on oligosaccharides such as stachyose and raffinose, while yeasts, spores, and metazoans depend primarily on disaccharides, particularly sucrose and trehalose, and on glycerol. As in many other anhydrobiotes, a metabolic preparatory stage in which these carbohydrates are synthesized from glycogen reserves appears essential for anhydrobiosis in tardigrades, and thus limits physiological tolerance of desiccation rate. Adaptive processes such as tun-formation in tardigrades and bdelloids, coiling in nematodes, and gradient-dependent changes in integumental permeability, retard water losses during preliminary desiccation and exert important influence on survival in xeric extremes. In tardigrades, cryobiosis, or cold-induced cryptobiosis, differs from anhydrobiosis in several important details. Tun formation is not essential for survival, and tolerance of cooling rate depends on the ability to inhibit intracellular freezing. Unlike many cold-tolerant arthropods, tardigrades are freeze-tolerant. Extracellular freezing is promoted by one or more ice-nucleating proteins in Adorybiotus coronifer, and occurs at high temperatures close to 0 °C. Tolerance of variable cooling rates to sub-freezing temperatures in this species does not seem to depend on trehalose synthesis, although a role of other possible intracellular cryoprotectants is likely. It is presently unclear whether cryobiotic tardigrades undergo cytoplasmic vitrification, or whether freeze-dehydration and colligative lowering of cytoplasmic water activity renders the remaining water unfreezable. The profound tolerance of environmental extremes displayed by cryptobiotic organisms apparently depends on the loss of a liquid water phase with accompanying metabolic depression as elegantly described by Clegg's vicinal network model. Thus protected from temperature- and solute-dependent effects on reaction kinetics, and (in part) from destructive free-radical oxidation, cryptobiotes can retain viability in a near-inert state for decades. Disruption of multi-subunit enzyme reactions accompanying loss of the vicinal water fraction may control the decline in metabolism, but also eliminates important free-radical scavenging pathways. Glycerol partly offsets this, acting as an antioxidant, but progressive free-radical oxidation in cryptobiotes may set the upper limit to longevity under aerobic conditions. While we can make many inferences of the physiology of cryptobiosis in tardigrades based on information gathered from other cryptobiotic organisms, specific studies on tardigrades are few, and encompass only a small number of species. This should prove a fruitful field for future research.
Mr. Chairman. Distinguished ladies and gentlemen. As Dean of Science it is a great honour on behalf of the University of Copenhagen and the Faculty of Science to welcome all of you here to the 8th International Symposium on Tardigrada. We are especially happy to have you here at the August Krogh Institute (named after our well-known Nobel Prize winner in Physiology), because on September 1st we celebrate the establishment of the Faculty. So coming here and honouring our 150 year anniversary jubilee help us to promote the importance of science in our society. The University was founded in 1479 as a theological catholic school. It broke down in 1530 and was reestablished in 1537 after the reformation. Right from the start in 1479 there was science thought of at the university. Mathematics and Astronomy. And Zoology became a subject over the centuries together with other subjects which are today regarded as science. But only in 1850 did we become an independent Faculty thanks to the effort and progress done by the Danish Chemist H.C. Ørsted.
The oribatid mite Scutovertex pileatus sp. nov. is described on the basis of adult individuals originating from southern Austria (Carinthia). The new species shows the typical habitus of Scutovertex and is distinguished by the cerotegument and cuticle forming irregular nodules and bars over the entire body; the rostrum with two visor-like projections, with the ventral projection larger and arched ventrally; short lamellar setae; two pairs of converging ridges between the lamellae; small notogastral setae that are not broadened distally; and a sclerotized rib across the mentum. Furthermore, DNA sequences of the COI gene (region 2, 567 bp) of S. pileatus were compared with those of S. minutus, S. sculptus, using Cymbaeremaeus cymba as the outgroup. Molecular data unambiguously support the discreteness of all three species by placing them reciprocally monophyletic, as well as by large genetic divergences. Interspecific distances among C. cymba, S. minutus, S. pileatus and S. sculptus amounted to 13.7–29.9%.
Two new water mite species of the genus Hygrobates Koch, 1837 (Acari, Hydrachnidia, Hygrobatidae) were found to live parasitic on newts of the genus Paramesotriton Chang, 1935 (Amphibia, Caudata, Salamandridae) from Vietnam and Laos: Hygrobates forcipifer sp. nov. and H. ancistrophorus sp. nov. The H. salamandrarum-group is defined, that now includes three species from Southeast Asia. Males and females of both new species are described, as well as larvae and deutonymphs of the Vietnamese species. These data provide the first record of males, nymphs and larvae of the species-group. The systematic position of the group, as well as the parasite–host association and the lifecycle of the species are discussed. Furthermore, the character states of the striking mouthparts, particularly modified as an adaptation for penetrating the amphibian skin, the genital skeleton and the larval morphology are examined.
The position of the family Myobiidae in the infraorder Eleutherengona (Prostigmata) was analyzed with a cladistic parsimony approach for the first time. Species of the genera Anystis von Heyden (Anystidae), Pomerantzia Baker (Pomerantziidae), and Walytydeus Kuznetzov (Paratydeidae) were selected as outgroups. Among Eleutherengona, species of the following genera were selected as ingroup taxa: Hirstiella Berlese (Pterygosomatidae), Eucheyletia Baker, Cheyletiella Canestrini (Cheyletidae), Syringophilus Heller (Syringophilidae), Tarsocheylus Berlese (Tarsocheylidae), Heterocheylus Lombardini (Heterocheylidae), Pygmephorus Kramer (Pygmephoridae), Raphignathus Dugès (Raphignathidae), Neognathus Willmann (Caligonellidae), Storchia Oudemans (Stigmaeidae), and Tuckerella Womersley (Tuckerellidae). Three most parsimonious trees with similar topology were obtained. In all these trees, the family Myobiidae is situated outside of the clade joining the higher Raphignathae (Raphignathoidea and Cheyletoidea) and represents a branch within the earlier derivative Raphignathae. This result is based primarily on characters from leg setation and postembryonic development. The conclusion from this topology is that myobiid mites have developed some gnathosomal structures convergently with Cheyletoidea, including the stylet-like chelicerae and stylophore fused with the subcapitulum. The evolution of animal eleutherengone parasitism is discussed. Parasitism arisen independently in numerous phyletic lineages or superfamilies of Eleutherengona. The representatives of some phylogenetically distant eleutherengone lineages developed similar adaptations to predation and parasitism. However, in spite of some similarities in these adaptations, the evolutionary trends and pathways for switching to a parasitic mode of life are quite different in particular eleutherengone lineages.
Many papers describe the cnidae from acontiarian sea anemone species, but comparative studies involving significant data amounts, combined with adequate statistical treatment have not been realized. The aim of the present paper is to carry out a comparative study of acontian cnidae from the species Haliplanella lineata (Verrill, 1869), Tricnidactis errans Pires, 1988 (Haliplanellidae) and Anthothoe chilensis (Lesson, 1830) (Sagartiidae). Five living specimens of each species were used; the length of 50 unfired capsules was measured and taken randomly from the following nematocyst categories: b-rhabdoids, p-rhabdoids B1b, p-rhabdoids B2a. A total of 2,000 measurements was done. The data were analyzed with descriptive statistics (mean, standard deviation, median, maximum, minimum, and semiinterquartile range) and Shapiro-Wilks test, Box-Cox transformation, Kruskal-Wallis test and single factor ANOVA. The normal distribution of the dataset must be tested for each nematocyst type in any quantitative study of the cnidae. We conclude that variation in nematocyst size should not be used as an element of conclusive value in the diagnosis of species of acontiarian sea anemones. For these purposes, other characters have to be used to define precisely each taxon, including qualitative variation of the cnidae.
Interest in parasitoids has grown with the recognition that host-parasitoid systems offer opportunities to examine fundamental questions in behavioural and evolutionary ecology. Tachinid flies of the Ormiini possess a conspicuously inflated prosternal region, enabling them to detect the mating songs of their hosts. This speciality makes them a highly suitable group for studies of adaptive radiation. To emphasise further research in this important group of parasitoids, their biogeography and host species are summarised.The Ormiini are a particularly small group, containing only 68 described species of predominantly tropical, especially neotropical forms. A table of host-parasitoid relations reveals that predominant parasitism is of bushcrickets. The exploitation of cricket songs appears to be a derived pattern that evolved as a host switch some time after the Eocene.Hypotheses concerning fly-host coevolution and the reasons for the development of hearing are discussed, and include the question of mate finding and avoidance of bats as predators.
We used SEM to investigate the morphology of the cypris larvae from a range of species of the Cirripedia Acrothoracica, representing all three families and including the first detailed account of cyprids in the highly specialized Cryptophialidae. Special attention was given to the head shield (carapace), the lattice organs, the antennules, the thoracopods, the telson and the furcal rami. The cypris larvae of the Acrothoracica fall into two morphological groups; those of the Trypetesidae and Lithoglyptidae have a well-developed carapace (head shield) that can completely enclose the body and sports fronto-lateral pores, numerous short setae and lattice organs perforated by numerous small, rounded pores and a single, conspicuous terminal pore. The fourth antennular segment has the setae arranged in subterminal and terminal groups. There is a developed thorax with natatory thoracopods and a distinct abdomen and telson. In comparison, the cyprids of the Cryptophialidae exhibit apomorphies in the morphology of the carapace, the antennules and the thorax, mostly in the form of simplifications and reductions. They have a much smaller head shield, leaving parts of the body directly exposed. The shield is conspicuously ornamented by deep pits and hexagonally arranged ridges and bears a few, very long setae but lacks fronto-lateral pores. The lattice organs have numerous elongated pores, but no large, terminal pore. The fourth antennular segment has all the setae clustered in one terminal group. The thorax and thoracopods are rudimentary and not suitable for swimming. These reductions and simplifications in morphology correlate with cryptophialid cyprids being unable to swim. They can only disperse by antennular walking resulting in small, but highly gregarious populations of adults. The variations in antennular morphology and telson structure were traced for the genera of the families Lithoglyptidae and Trypetesidae. The traditional non-cladistic taxonomy in the suborders Pygophora (Cryptophialidae+Lithoglyptidae) and Apygophora (Trypetesidae) was based largely on symplesiomorphies in adult morphology and cannot be upheld. The Lithoglyptidae and Trypetesidae may form a monophylum, but evidence remains scarce. We expect that the use of larval (cyprid) characters will in the future play an important part in more detailed phylogenetic analyses of the Acrothoracica and also shed new light on their reproductive ecology.
The external morphology of the dwarf males of Lithoglyptes mitis, Lithoglyptes bicornis, Kochlorine hamata, Kochlorine sp., Cryptophialus hoegi, Cryptophialus sp., and Trypetesa lampas was examined under SEM. New data on the cuticular structures are compared with existing information on acrothoracican and thoracican males. The structure of the male mantle differs among acrothoracican families and thus may have taxonomic value.
We describe the external morphology of the two cypridiform larval instars (first and second ascothoracid-larvae, or “a-cyprids”) of the ascothoracidan genus Dendrogaster. Ascothoracid-larvae of five species were studied with light and scanning electron microscopy, including both ascothoracid-larval instars in Dendrogaster orientalis Wagin. The first and second instars of the ascothoracid-larvae differ in almost all external features. The carapace of instar 1 has a smooth surface and lacks pores, setae, and lattice organs, while instar 2 has all these structures. The antennules of the first instar have only a rudimentary armament, the labrum does not encircle the maxillae, thoracopods 2–3 are not armed with a plumose coxal seta, and the abdomen is four-segmented (versus five-segmented in instar 2). Thus, the first ascothoracid-larva of Dendrogaster represents a transitional, generally brooded stage between the naupliar stages and the dispersive and fully functional second ascothoracid-larva that accomplishes settlement. The presence of two instars of ascothoracid-larvae (a-cyprids) in members of the order Dendrogastrida differs from the single cypridiform instar found in the Cirripedia (cyprid) and Facetotecta (y-cyprid), and we discuss the evolutionary significance of these ontogenies. We found lattice organs in both the second ascothoracid-larvae and in adult males of Dendrogaster. We could not observe both ascothoracid-larvae and males in any single species, but our data suggests that the lattice organs change significantly at the molt between these two instars. The lattice organs of second ascothoracid-larvae have no distinct keel and are situated in wide, shallow pits, whereas they have the ground pattern “crest-in-a-trough” morphology in adult males of two additional species examined for comparison. The positions of the terminal pores of lattice organs 1 and 2 also seem to change during maturation. These findings show that comparative data on lattice organ morphology for phylogenetic purposes must derive from strictly homologous instars, viz., the second ascothoracid-larva (a-cyprid) of the Ascothoracida, the y-cyprid of the Facetotecta, and the cyprid of Cirripedia. The ascothoracid-larvae of Dendrogaster and those of the family Ascothoracidae have four pairs of lattice organs, which suggests that this genus and family form a monophylum, to the exclusion of Ulophysema, which then brings into question the monophyly of the Dendrogastridae. Ulophysema is currently placed in the Dendrogastridae, but its second ascothoracid-larva has lattice organs of different and more plesiomorphic number and morphology. We briefly review lattice organ morphology across the Thecostraca. These organs are normally considered structures of the cypridiform larva and their presence in adult (males) Ascothoracida is unique in the Thecostraca. The continued morphological modification of these sensory structures in males compared to ascothoracid-larvae may suggest that they originated in adult thecostracans, but have come to be functional in the cypridiform larvae as well.
The phenotypic consequences in the house mouse (Mus musculus domesticus) of the transition from an ordinary field-dwelling rodent to a species that is dependent on human populations was studied by investigating the morphometric variation of non-commensal populations of M. m. domesticus from Syria, Jordan, SW Iran, and Libya and comparing them with that of conspecific commensal populations from Eastern Turkey, Greece, and Bulgaria. Commensal populations of M. musculus musculus from the Czech Republic were used as an outgroup. About 849 adult specimens of M. musculus were analysed by multivariate procedures based on standard molar, skull and body measurements. As expected, there was considerable variation among the studied populations and a good correspondence between morphometric and geographic distances. The resulting morphometric tree was consistent with the hypothesis that the original radiation of M. m. domesticus took place somewhere in the Near East. Commensal populations of M. m. domesticus form a single derived branch. Specimens originating from four different sites in eastern Syria showed the greatest similarity to one another and possessed relatively bigger molars than the other studied populations. Commensal populations were characterised by longer tails when compared to non-commensal populations, which suggests an adaptation for living in a more three-dimensionally heterogeneous environment for commensal populations.
Drakensbergianella rudebecki, a new genus and new species of flea beetle (Chrysomelidae, Alticinae) found at high elevations from Southern Africa (Drakensberg mountains) is described. This new genus is closely related to the genus Gabonia Jacoby, 1893 but is easily distinguishable mainly by: the metasternum shorter than the length of the middle coxal cavities; the legs with femora and tibiae clearly elongate, especially the hind ones; the antennae generally longer than body in both sexes, especially in males; the metafemoral spring with inner side of the ventral lobe not angled; the metathoracic wings strongly reduced. Line drawings of male and female genitalia, metafemoral springs, and scanning electronic micrographs of particular morphological aspects of the taxa considered are provided. Finally, a brief discussion about Gabonia and related genera in the Afrotropical region with a key for the identification, is also reported. Moreover, the following new combination is proposed: Longitarsus ruandensis Weise, 1910 = Montiaphthona ruandensis Weise, 1910 n. comb.