Fig 6 - uploaded by Jibom Jung
Content may be subject to copyright.
Major Group (MAG) of Pagurus minutus, male, sl 7.0 mm, MADBK 160706_070, right ambulatory leg 2 and dactyl of left ambulatory leg 2 detached. A, dorsal view; B, ventral view. Scale bars = 7 mm.

Major Group (MAG) of Pagurus minutus, male, sl 7.0 mm, MADBK 160706_070, right ambulatory leg 2 and dactyl of left ambulatory leg 2 detached. A, dorsal view; B, ventral view. Scale bars = 7 mm.

Source publication
Article
Full-text available
Citation: Jung J, Jung J, Kim W. 2018. Subdividing the common intertidal hermit crab Pagurus minutus Hess, 1865 (Decapoda: Anomura: Paguridae) based on molecular, morphological and coloration analyses. Zool Stud 57:61. (2018) A phylogenetic study was conducted to investigate whether distinct genetic groups are present within the East Asian Pagurus...

Citations

... There are currently no genetic studies on the diversity or population genetics of these species. It is possible that cryptic species are present among these nominal species across the Indo-Pacific region, like for many other barnacles, as well as for hermit crabs and other decapods (Chan et al. 2007;Tsang et al. 2012;Jung et al. 2018;Shih and Poupin 2020) or that they are homogeneous populations across large geographical expanses (see example of intertidal blennies in Hongjamrassilp et al. 2020). Future research should also focus on the diversity and biogeography of rhizocephalan species in India, as this superorder of barnacles remains extremely understudied in India. ...
Article
Full-text available
The present work studied the diversity of intertidal, epibiotic, and fouling barnacles in the state of Gu�jarat, northwest India. In total, eleven species belonging to eight genera and five families were recorded in the present study. The Arabian intertidal species Tetraclita ehsani Shahdadi, Chan & Sari, 2011 and Chthamalus barnesi Achituv & Safriel, 1980 are common in the high- and mid-intertidal rocky shores of Gujarat suggesting that the Gujarat barnacle assemblages are similar to the assemblages in the Gulf of Oman Ecoregion. The biogeographical boundary between the Gulf of Oman and Western Indian ecore�gions for barnacles should probably extend southward towards the waters adjacent to Mumbai, where Indo-Pacific species of intertidal barnacles dominate. This study provides the first reports of the common widely distributed balanomorph barnacles Striatobalanus tenuis (Hoek, 1883), Tetraclitella karandei Ross, 1971, Amphibalanus reticulatus (Utinomi, 1967), and lepadid barnacle Lepas anatifera Linnaeus, 1758 in Gujarat, as well as of the chthamalid barnacle Chthamalus barnesi in India.
... Colour difference is sometimes reflected by incipient speciation. For instance, an intertidal pagurid hermit crab (Pagurus minutus Hess, 1865) is a species that exhibits several colour variations on the lateral surfaces of its ambulatory legs which reflect genetically differentiated local populations; P. minutus are possibly separated into three groups at the species level (Jung et al., 2018). ...
Article
Full-text available
Members of Clibanarius virescens show considerable intraspecific colour variation, including colouration of the second/third pereopods (green/white) and the dactyls of the second/third pereopods (with or without dark bands/patches). However, factors inducing these colour variations have not yet been elucidated. Here, we investigated the occurrence of colour variation in this species with particular emphasis on change of colouration associated with growth stage and region in specimens from tropical/subtropical to warm temperate areas in the Indo–West Pacific, including evidence from molecular phylogeny based on the cytochrome c oxidase sub-unit I (COI). We have, then, clarified that the colouration on the pereopod dactyls gradually changed from solid colour (yellow/white) to having dark-coloured area(s) or transverse band(s) as a result of the growth stage. The frequency of occurrence of the solid colour dactyls was higher than those of other colour types in tropical regions. Our results also indicated that the white ambulatory leg type was the colouration type that was frequently seen in juvenile stages.However, significant genetic differences were not detected between each colouration determined by molecular analysis of samples from 14 localities in the Indo-West Pacific region;in contrast, two genetically differentiated regional populations (North Australia; Phuket,Thailand; and Lombok, Indonesia) were detected. The present study, therefore, emphasizes the necessity for further study on the colour variation of marine animals focusing on growth stages and regional differences, with molecular data to facilitate the research on adaptation and/or speciation, especially in geographically widely distributed species.
... Species assemblages of intertidal and shallow water barnacles in Korean waters vary among the three marine ecoregions. Such variation in assemblages is also reported in intertidal hermit crabs and their parasitic rhizocephalan barnacles (Jung et al., 2018. From multivariate nMDS plots, there is a large degree of overlap of the clusters from the Yellow Sea and East China Sea ecoregions, suggesting there are large groups of species shared between these two ecoregions. ...
Article
The coastline of the Korean Peninsula is influenced by three major oceanographic ecoregions, including the estuarine Yellow Sea ecoregion on the west coast, the warmer and saline East China Sea ecoregion on the south coast, and the cold East Sea ecoregion on the east coast. The influence of these marine ecoregions on the distribution of intertidal barnacles has not been extensively studied. The present study examines the biogeography of thoracican barnacles from intertidal and shallow subtidal zones, along the coasts of Korea. Twenty-one species in seven families were identified, including three species of coral-associated barnacles. Species composition varied significantly in the three marine ecoregions. Multivariate analysis showed barnacle assemblages were significant among the three ecoregions, although there are large overlaps of clusters between the Yellow Sea and East China Sea ecoregions. The estuarine species, Fistulobalanus albicostatus , occurred mainly in the Yellow Sea ecoregion; warm-water species, Tetraclita japonica , and sponge inhabiting barnacles Euacasta dofleini were observed in the East China Sea ecoregion; and cold-water species, Balanus rostratus and Perforatus perforatus , were found in the East Sea ecoregion. Four invasive barnacle species were recorded and the European barnacle Perforatus perforatus expanded its range northward from its recorded distribution nine years earlier. The cold-water species, Chthamalus dalli and Semibalanus cariosus , previously recorded in the East Sea ecoregion, were absent in the present survey. A trend of increasing seawater temperatures in Korean waters may have a significant impact on the distribution of cold-water species and enhance the northward invasion of P . perforatus .
... In this study, we tested the validity of the morphological and ecological characters as evidence of the taxonomic divergence of these four Pagurus species via DNA barcoding. Four Pagurus species were identified based on morphology, according to Jung et al. (2018a), and whole-body photographs were taken ( Fig. 1) from 11 collecting sites (Fig. 2). For DNA barcoding, the cytochrome c oxidase subunit I (COI) of four Korean Pagurus species were sequenced with the universal primers LCO1490 and HCO2198 (Folmer et al., 1994), and sequence variations were determined based on known congener sequences (Jung et al., 2018a). ...
... Four Pagurus species were identified based on morphology, according to Jung et al. (2018a), and whole-body photographs were taken ( Fig. 1) from 11 collecting sites (Fig. 2). For DNA barcoding, the cytochrome c oxidase subunit I (COI) of four Korean Pagurus species were sequenced with the universal primers LCO1490 and HCO2198 (Folmer et al., 1994), and sequence variations were determined based on known congener sequences (Jung et al., 2018a). The mitochondrial 16S rRNA of these species were also sequenced, using the primers 16SH2 and 16SL2 (Schubart et al., 2000). ...
Article
Full-text available
Pagurus is the most diverse hermit crab genus in Korea. In this study, the cytochrome c oxidase subunit I (COI) and 16S rRNA of 24 individuals from four Korean Pagurus species (i.e., 7 Pagurus brachiomastus, 8 P. proximus, 8 P. simulans, and 1 P. rectidactylus) were sequenced and analyzed. No genetic difference was found between the COI and 16S rRNA sequences of P. brachiomastus and P. simulans, and the COI sequences of P. rectidactylus and P. quinquelineatus (comparative species from NCBI). Considering the morphological and ecological characteristics together, we assume that P. simulans and P. rectidactylus are subspecies of P. brachiomastus and P. quinquelineatus, respectively. This study should facilitate further research on the taxonomic status of these species.
... Several studies have successfully used DNA barcoding to distinguish closely related species of crustaceans, including intertidal and terrestrial crabs (Lai et al. 2017;N. K. Ng et al. 2018;Shih et al. 2019a), fiddler crabs (Shih et al. , 2019cThurman et al. 2018), freshwater crabs (Cumberlidge & Daniels 2014;Huang et al. 2017), freshwater shrimps (Shih et al. , 2019a, and hermit crabs (Hamasaki et al. 2017;Jung et al. 2018) as well as the larval stages of crustaceans and fishes (Chen et al. 2013;Wong et al. 2014;Chu et al. 2019). ...
Article
Species of the varunid genus Parahelice Sakai, Türkay & Yang, 2006, inhabit high intertidal areas of oceanic islands of the tropical Indo-West Pacific region. As several species of Parahelice and Pseudohelice subquadrata (Dana, 1851) were found to be sympatric in some places, and their morphological differences are minor, especially in females, the misidentification of species is not uncommon in the literature. In this study, the DNA barcoding marker, mitochondrial cytochrome c oxidase subunit I (COI), was applied to confirm species identities and this was correlated with the specific characters of males and females. Distributions of three species of Parahelice were also updated, with Par. daviei (Sakai, Türkay & Yang, 2006), Par. pilimana (A. Milne-Edwards, 1873), and Par. pilosa (Sakai, Türkay & Yang, 2006) being new records to Taiwan, and Par. pilosa new to Bali, Indonesia.
... The identification of species and the acquisition of taxonomic data for Milnesium species may pose a serious challenge when dealing with samples where multiple species with different CCs are present. Only a combination of various techniques, including DNA barcoding and culturing, allows for the collection of reliable data and confident interpretations (see such successful approaches in other animal groups: Shih et al. 2017;Chen et al. 2018;Jung et al. 2018;Hosoishi and Ogata 2019). In return, the collected data for further analysis are richer and no diversity is omitted due to difficulties in handling the material. ...
Article
Full-text available
The tardigrade fauna of Iceland has been a subject of studies since mid XX century. So far, only a single species of the genus Milnesium has been reported from the island, M. tardigradum, which at the time was assumed to have a cosmopolitan distribution. However, the record comes from before the redescription of M. tardigradum, thus the validity of the Icelandic report is questionable. Some species of Milnesium are characterised by developmental variability, which is most pronounced in the morphology of secondary branches of claws, exhibited by shifts in the number of spurs. In this contribution, we present a case study in which multiple claw configurations (CC) were found in a single lichen sample from Iceland, indicating the presence of more than one species and/or ontogenetic variability. To elucidate this puzzle, we utilised a range of integrative tools, including detailed morphology, morphometry, barcoding and development tracking. We present the workflow, which enabled us to collect the data for each species/morphotype. In result, we revealed the presence of three species, two characterised by ontogenetic CC change (M. variefidum and a new species) and one with a stable CC (a new species). Here, we describe one of these new species, M. pseudotardigradum, which is extremely similar to M. tardigradum, but can be phenotypically differentiated by a unique, double CC change pattern. Citation: Surmacz B, Morek W, Michalczyk Ł. 2019. What if multiple claw configurations are present in a sample? A case study with the description of Milnesium pseudotardigradum sp. nov. (Tardigrada) with unique developmental variability. Zool Stud 58:32.
... The molecular analysis methods followed those described by Jung et al. (2018a). The mitochondrial sequences of the collected specimens obtained by DNA extraction were checked and edited using SeqMan 5.0 (DNASTAR, Madison City, WI, USA) and DNA Sequence Polymorphism (DnaSP) version 6 software (Rozas et al. 2017); they were aligned using a ClustalW interface ClustalW in MEGA7 (MEGA, PA, USA) (Kumar et al. 2016). ...
... These results suggest that the present specimen is not P. postica, but an unreported species, though further data are needed to confirm this. Jung et al. (2018a) showed that the Korean and Taiwan-Okinawa populations of Pagurus minutus are different based on molecular, morphological, and color characteristics. Morphological examination of the host P. minutus individuals infested with Peltogaster postica shows that the host reported by Yoshida et al. (2011) belonged to the Taiwan-Okinawa Group (TOG), whereas the host in this study belongs to the Major Group (MAG). ...
Article
Full-text available
We performed a diversity study on parasitic barnacles (Crustacea: Cirripedia: Rhizocephala: Peltogastridae) that parasitize hermit crabs in Korea. Their morphological, ecological, molecular (cytochrome c oxidase subunit I, 16S rRNA), and biogeographical characteristics were examined. Three species were identified based on GenBank sequences and the external morphology of the externa. In addition, this study proposes four new candidate species. This is the first report on the family Peltogastridae from Korea. Six hermit crab species were found to be new hosts to peltogastrids. Korean peltogastrids are less prevalent on their host hermit crabs than those from Japan are, especially in the west coast of Korea. Peltogasterella gracilis is widely distributed throughout Korea, Peltogaster lineata is located on the east coast, and Peltogaster postica is only located on Jeju Island.
... Furthermore, their molecular identification is difficult because of the lack of DNA sequences in public databases such as GenBank. In this study, morphological characterization of diogenids was performed according to Jung et al. (2018a), with some modifications and the photographs taken their whole bodies were presented (Fig. 1). For DNA barcoding approach, the cytochrome c oxidase subunit I (COI) sequence of six Korean diogenid species were determined with universal primers LCO1490 and HCO2198 (Folmer et al., 1994) and sequences variations were conducted with known congener sequences (Negri et al., 2014). ...
Article
Full-text available
In this study, cytochrome c oxidase subunit I(COI) sequences of 17 individuals from six Korean diogenid species(i.e., 2 Areopaguristes japonicus, 4 A. nigroapiculus, 3 Paguristes digitalis, 4 P. ortmanni, 3 Diogenes edwardsii, and 1 Ciliopagurus kempfi) were determined and analyzed. The DNA barcoding results of this study were consistent with the morphological identification of these six species. Interspecific variations of COI sequences within six Korean diogenid species exceeded the minimum interspecific variation of diogenid hermit crabs in previous studies. Little intraspecific variation exists except for P. digitalis. This study should facilitate further molecular taxonomy of East Asian diogenids.
... and S. grygieri evolved from a common ancestor and that the genus Synagoga exhibits the major Tethyan reliction pattern that is also characteristic of some ascothoracidans and barnacles (Newman and Ross 1971;Newman and Tomlinson 1974;Foster 1981;Kolbasov 2009;Kolbasov et al. 2015). Currently, studies of diversity of Ascothoracida are still based mainly on morphological approaches, future directions can involve molecular techniques to examine cryptic diversity and population genetics of Ascothoracida (see approaches in Chai et al. 2017;Chang et al. 2017;Ma et al. 2019;Jung et al. 2018) ...
Article
Full-text available
A new ascothoracidan species has been discovered off Taiwan in the north part of the west Pacific at SCUBA depths. Twelve specimens including both sexes of the new species, described herein as Synagoga arabesquesp. nov. , were collected from colonies of the antipatharian Myriopathes cf. japonica Brook, 1889. Three previously described species of Synagoga , morphologically the least specialized ascothoracidan genus, have been found as ectoparasites of antipatharians and an alcyonarian, whereas all other records of this genus have been based on specimens collected from the marine plankton. This is the second study of a new form of Synagoga to be based on more than a few mature specimens of a single sex or on a single juvenile. Furthermore, it is the second in which SEM has been used to document the fine-scale external morphology. The position of terminal pores in the anterior pairs of the lattice organs is different in Synagoga arabesquesp. nov. than those in S. grygieri Kolbasov & Newman, 2018 and S. millipalus Grygier & Ohtsuka, 1995. Species of Synagoga are small, host-specific predators or ectoparasites of antipatharians. This genus exhibits a major Tethyan reliction pattern.
... Future studies are needed to clarify whether Planotergum kowalevski is endemic to the Red Sea or to the western/northwestern Indian Ocean. This should also involve molecular approaches to study the population genetics of Planotergum in the Red Sea and Pacific and Indian Oceans (e.g., Chai et al. 2017;Jung et al. 2018). ...
Article
Full-text available
A new species of the aberrant monotypic genus Planotergum Balss, 1935 (Brachyura: Majidae: Planoterginae) is described from the southern part of the Red Sea, based on a single female recently found in the collection of the Zoological Museum of Moscow State University. The new species is clearly distinguished from Planotergum mirabile Balss, 1935 in the form of carapace, antennal article and third maxilliped, as well as morphology of the ambulatory legs. The record extends the known range of Planotergum, previously known only from the eastern Indian Ocean and Western Pacific, by more than 7000 km.