Isopod Family Research Articles

Temporal variation in population structure of the isopod Urobopyrus processae Richardson, 1904 (Isopoda: Bopyridae) infesting the branchial chamber of the night shrimp Ambidexter symmetricus Manning and Chace, 1971 (Decapoda: Processidae)

Caridean shrimps are often infested by ectoparasites from the isopod family Bopyridae. Urobopyrus processae is a widespread species of bopyrid parasitizing the branchial (gill) chambers of members of the caridean family Processidae, including Ambidexter symmetricus. We examined hypotheses on differential infestation based on gender, castration of the host by the parasite, correlation between host and parasite size, and the fecundity of female parasites. Infestation rates varied from 1.3 to 32.1% between 2010 and 2011. Infested shrimps ranged from 1.26 mm to 6.24 mm carapace length (CL) between 2010 and 2011. Female shrimps were infested at a higher rate than males (2010 P = 0.0376; 2011 P = 0.0023). We report for the first time the differential selection between left and right branchial chambers in a caridean shrimp by a bopyrid parasite (P = 0.0209). Female parasite total length (TL) increased with host size (CL) in both years of sampling (2010 R2adj = 0.6863; 2011 R2adj= 0.8206). The size of male parasite TL was explained by both host CL (2010 R2adj = 0.4591; 2011 R2adj = 0.5490) and parasite female TL (2010 R2adj = 0.5606; 2011 R2adj = 0.6195). The number of embryos in a brood of the female parasite (85-3096) was varied positively with female TL (R2adj = 0.625). Our results show that the bopyrid-shrimp host relationship in processids is typical of those studied in other carideans, indicating similar selective pressures act on bopyrids infesting the branchial chambers of shrimps.

Joeropsididae Nordenstam, 1933 (Crustacea, Isopoda, Asellota) from the Lizard Island region of the Great Barrier Reef, Queensland, Australia.

The marine isopod family Joeropsididae (Asellota) is documented for the Lizard Island region of the Great Barrier Reef, Australia. Fifteen species of Joeropsis are recorded, including ten new species; descriptive notes are provided for five species that lacked adequate material for description. A revised family and genus diagnosis is presented together with comments on the most useful characters for species identification and a key to Joeropsis of the Lizard Island region.

An account of the Ischnomesidae (Peracarida, Isopoda) from the Kuril–Kamchatka Trench and abyssal plain (Northwest Pacific) with the description of two new species

During the German–Russian expedition KuramBio (Kuril–Kamchatka Biodiversity Studies) from board of the RV Sonne to the Kuril–Kamchatka Trench and adjacent abyssal plain, benthic samples were taken by means of a camera-epibenthic sledge. Amongst one of the most diverse macrobenthic taxa, the Isopoda (Crustacea, Malacostraca), Ischnomesidae were the fifth most abundant isopod family in the Kuril–Kamchatka area and were sampled with 24 species from 5 genera in 21 hauls at 12 stations. Fortimesus occurs most frequently in the samples (36% of all Ischnomesidae sampled), followed by Stylomesus (26%), Heteromesus (23%), Ischnomesus (10%) and Gracilimesus (4%). Number of ischnomesid individuals is highest at station 10-12 with 35 specimens, followed by station 12-4 (30 ind.), station 6-12 (29 ind.), station 9-9 (28), and station 1-11 (24). At station 4-3 only 1 specimen was found. A key to all genera of Ischnomesidae is provided.Two new species from two genera: StylomesusWolff, 1956 and FortimesusKavanagh and Wilson, 2007 are described from the KuramBio material. Stylomesus malyutinae sp. nov. is distinguished by the smooth body surface, the shape of pleotelson and the length of uropods from other species of the genus from the Northwest Pacific Ocean. Fortimesus trispiculum sp. nov. is characterised by anterolateral projections of pereonites 1–3 which are forming an angle of about 45° with the longitudinal body axis decreasing in length from anterior to posterior.

New data on pacific Microcope (Crustacea, Isopoda, Munnopsidae) with descriptions of two new species and redescription of M. ovata ( )

The isopod family Munnopsidae Lilljeborg, 1864 was the most diverse and species richest family among all macrobenthic organisms collected during the expedition KuramBio in the abyssal area off the Kuril–Kamchatka Trench (R.V. Sonne, 2012). The munnopsid genus MicrocopeMalyutina, 2008, represented by two species, was one of the most abundant and frequent isopod genera sampled at all stations. Microcope ovata (Birstein, 1970), the only known Pacific species of Microcope to date, is redescribed based on the new collections, since the types of the species were lost. Descriptions of a new species from the KuramBio samples, Microcope stenopigussp. nov. and a new species from the opposite side of Pacific Ocean, from the southeastern Australian slope, Microcope justisp. nov., are presented herein. These findings increase the number of described species of Microcope to five and extended the geography of the genus from the previously known South Atlantic, Antarctic and the northwestern Pacific to the new localities from the southwestern Pacific. The depth range for the genus was also extended from 2014–7370m, to 427–7370m. A map of the distribution of the genus Microcope and a key to the described species of Microcope are provided.

New species of the deep-sea munnopsid genus Tytthocope (Crustacea, Isopoda, Asellota) from the South Atlantic and the Southern Ocean.

In the benthic samples collected during the deep-sea expeditions ANDEEP from the Weddell Sea and DIVA from the Argentine Basin the isopod family Munnopsidae was the most specious and numerous. Among the collected munnopsids three new species of Tytthocope Wilson & Hessler, 1981 have been discovered. Tytthocope is one of six genera of the subfamily Eurycopinae. It differs from other genera of the Eurycopinae by having a strongly reduced pereonite 7 and inflated pleotelson. Until now the genus consisted of five described species: four of them are known from the northern Atlantic and only one species, T. sulcifrons (Barnard, 1920) was described from the southern Atlantic off the South Africa coast. The five known species of Tytthocope have been recorded from depths less than 1461 m. Descriptions of three new species of Tytthocope collected in the South Atlantic and Southern Ocean at depths between 1530-4608 m, T. divae sp. nov., T. fahrbachi sp. nov. and T. longitelson sp. nov. are presented in the paper. T. sulcifrons is redescribed herein based on the type material.

Composition and distribution of selected munnopsid genera (Crustacea, Isopoda, Asellota) in Icelandic waters

The Greenland–Scotland Ridge (GSR) is a major topographic feature, extending from Greenland to Scotland. It constrains the water exchange between the northernmost North Atlantic Ocean and the Greenland, Iceland and Norwegian Seas (GIN Seas) and thus forms a potential barrier for faunal exchange from the Arctic to the North Atlantic (and vice versa). Recently an increase in Atlantic water inflow has been observed, leading to changes in physical parameters (i.e. temperature and salinity), which may have an impact on the resident fauna. In this study, we analyzed the composition and distribution of six selected genera of the isopod family Munnopsidae (Crustacea) occurring north and south of the GSR. We examined 82 epibenthic sledge samples and 26 additional sub-samples taken in the course of the Benthic Invertebrates of Icelandic Waters (BIOICE) and Icelandic Marine Animals: Genetics and Ecology (IceAGE) projects, respectively, covering a total depth range from 103 to 2752m depth. Overall, 58 of the evaluated stations originated in the area north of the GSR, while the remaining 50 samples were collected south of the ridge. In total, 10517 individuals could be assigned to 15 species, most belonging to the genus EurycopeSars, 1864. Due to the presence of the GSR as well as differences in the environment, we expected significant dissimilarities in faunal composition between the two study areas. However, most species (8) occurred on both sides of the ridge, while four species were restricted to the region north of Iceland, and three to the region south of the ridge. Depth (or factors related to depth) appeared to be the most important factor in driving distributional patterns of the studied species. Temperature was also an important driver, but not to the same extent as depth. On the contrary, salinity and sediment type did not have much influence on munnopsid distribution patterns. Hence, the presence of the ridge does not restrict faunal exchange between the northern North Atlantic Ocean and GIN Seas for most of the investigated species, which may be explained by the good swimming abilities and the ecological flexibility of these munnopsid species.

<p class="HeadingRunIn"><strong>Southern Ocean Macrostylidae reviewed with a key to the species and new descriptions from Maud Rise</strong></p>

The nine currently known Southern Ocean species of the asellote isopod family Macrostylidae Hansen, 1916 are reviewed. Modified diagnoses are provided. Two new species, Macrostylis matildae n. sp. and M. scotti n. sp. are formally described. M. setulosa Mezhov, 1992, and M. vinogradovae Mezhov, 1992 are redescribed. An identification key to all species is presented. Due to substantial damage and loss of type material, M. obscura (Brandt, 1992) and M. sarsi Brandt, 1992 are henceforward considered nomina dubia . DNA sequences were yielded for molecular characterization of both new species. A phylogenetic analysis shows, although from the same locality, both species are relatively distantly related. Huge divergence is discovered within Macrostylidae which casts doubt on the monotypy of the family.

Brasileirinidae, a new isopod family (Crustacea: Isopoda) from the cave in Bahia (Brazil) with a discussion on its taxonomic position

Brasileirinidae, a new isopod family (Crustacea: Isopoda) from the cave in Bahia (Brazil) with a discussion on its taxonomic position

Macrofaunal crustaceans in the benthic boundary layer from the shelf break to abyssal depths in the Ross Sea (Antarctica)

The New Zealand International Polar Year–Census of Antarctic Marine Life (NZ IPY-CAML) project added to previous benthic studies in the Ross Sea by extending sampling north from the continental shelf to previously unsampled areas of the shelf break, slope, abyssal plain and seamounts in the region. The aim of the current study is to give first insights into the deep-sea community structure of the Ross Sea focussing on a component of the benthic boundary layer that is macrofaunal crustaceans collected one metre above the seafloor. We assess changes in Ross Sea crustacean community composition from the shelf break (474 m) to the abyss (3,490 m) and compare the Ross Sea crustacean fauna to areas elsewhere in the Southern Ocean. Analyses reveal high relative abundances, suggesting an important role in the food web. Among the peracarid crustaceans, there was a decline in the proportion of amphipods with increasing depth. Three of 15 isopod families (Acanthaspidiidae, Nannoniscidae and Desmosomatidae) were identified to species level and about 72 % of the species were new to science. Isopod diversity in the Ross Sea abyss appears to be comparable to that in the highly speciose Weddell deep sea. Standardised sampling of these crustacean communities allows setting the biodiversity of the Ross Sea into a global context.

Brasileirinidae, a new isopod family (Crustacea: Isopoda) from the cave in Bahia (Brazil) with a discussion on its taxonomic position

The aquatic troglobiont Brasileirinho cavaticus (Crustacea: Isopoda: Calabozoidea), new genus and species is described from the karst cave of the State of Bahia, Brazil. Based on its unique pleonal features i.e. the total absence of female pleopods I–II, uniramous male pleopods I–II, minute, uniramous respiratory pleopods III–V in both sexes and pleotelson not exceeding 45% of the pleon length, a new family, Brasileirinidae, is created. Some biological, ecological and behavioral data for the species are provided together with the nature conservation issues. Additionally, an assignment of the new species to the suborder Calabozoidea is discussed through comparison with the other two calabozoid species, Calabozoa pellucida and Pongycarcinia xiphidiourus. For the latter species, some previously missing morphological details, as well as a new locality record, are provided. According to the updated morphological evidence, the previously assumed relationships of Calabozoidea are discussed and, consequently, the diagnostic characters of some taxa emended.

New Macrostylidae Hansen, 1916 (Crustacea: Isopoda) from the Gay Head-Bermuda transect with special consideration of sexual dimorphism

In the Asellota, sexual dimorphism is often characterized by males that show pronounced morphological differences after thefinal moult compared to females but also to sub-adult males. Such a sexual dimorphism may strongly complicate allocation ofthese terminal males to conspecifics. Consequently, we regard it to be a likely explanation for why in 50% of the described spe-cies of the family Macrostylidae Hansen, 1916, only one sex is known. Based on detailed description of two previouslyunknown species of the isopod genus Macrostylis Sars, 1864, the changes in the morphology that can occur during the finalmoult of the males are highlighted. M. dorsaetosa n. sp. is unlike any other species owing to the row of spine-like setae on theposterior margins of pereonites 5–6. M. strigosa Mezhov, 1999 shows remarkable similarity but lacks these setae. In M. papil-lata n. sp., cuticular ridges overlap posteriorly with the margin of the pereonites 1–4 and head forming a warty appearance. Thisspecies is easily identifiable and unlike any previously described macrostylid owing to the presence of the tergal articulationbetween pleonite 1 and pleotelson. Information for the identification of terminal males is provided and implications of our results for future taxonomic and systematic work on this isopod family are discussed.

Recent and fossil Isopoda Bopyridae parasitic on squat lobsters and porcelain crabs (Crustacea: Anomura: Chirostyloidea and Galatheoidea), with notes on nomenclature and biogeography

The parasitic isopod family Bopyridae contains approximately 600 species that parasitize calanoid copepods as larvae and decapod crustaceans as adults. In total, 105 species of these parasites (~18% of all bopyrids) are documented from Recent squat lobsters and porcelain crabs in the superfamilies Chirostyloidea and Galatheoidea. Aside from one endoparasite, all the bopyrids reported herein belong to the branchially infesting subfamily Pseudioninae. Approximately 29% (67 of 233 species) of pseudionine species parasitize squat lobsters and 16% (38 of 233 species) parasitize porcelain crabs. Bopyrids are found in five of six squat lobster families (lacking only in Kiwaidae) and the sole porcelain crab family Porcellanidae. Six pseudionine genera are shared between squat lobsters and porcelain crabs. The deepest bathymetric records of bopyrids on squat lobster hosts (5210 m), and records of swellings interpreted as indications of bopyrid presence in fossil host taxa are noted. Four nomenclatural issues are resolved and the proper form of citation for the French zoologist C. E. Hesse is provided. Biogeographic distributions for squat lobsters and porcelain crabs are discussed and compared to those of hermit crabs.

First record of Mothocya melanosticta Schioedte and Meinert, 1884 (Isopoda: Cymothoidae) from Egyptian pinecone soldierfish with special reference to its infestation status

Cymothoidae are cosmopolitan, ubiquitous, and nonspecific parasites of fish of different biotopes causing a significant economic loss to fisheries either by killing and stunting or simply by damaging their hosts. This study represents the first record of Mothocya melanosticta from the Red Sea, with a new host record in Myripristis murdjan (pinecone soldierfish), the other resident species of the fish-parasitic isopod family Cymothoidae in Egypt. The recovered Mothocya melanosticta was of moderate body size (17.7 × 8.2 mm) and had a cephalon with widely truncated rostrum, short pleotelson with uropod rami not extending beyond the telson, and the presence of a small rounded protrusion ranging in size from 0.3 to 0.5 mm on the lateral side of pereonite II. The overall prevalence was 31.25% and it was only found in the branchial cavity. The monthly and seasonal variation in infestation is reported.

Toward a Taxonomy of the Gnathiidae (Isopoda) Using Juveniles: The External Anatomy of Gnathia aureamaculosa Zuphea Stages Using Scanning Electron Microscopy

The juvenile stages of the isopod family Gnathiidae have a large impact on marine ecosystems through their parasitic interactions with marine fishes, as well as being a substantial food source for the cleaner fish guild. However, the taxonomy of Gnathiidae is based on non-feeding adult males. Adults are difficult to obtain owing to their cryptic lifestyle in the sea floor, while the juveniles can be collected in abundance either from their hosts or using emergence traps. Given the known diversity of the hosts, and assuming host partitioning among species, the diversity of gnathiids could be much greater than currently recognised. We argue that the systematics of this group should recognise this ecological role, and develop the taxonomy of the juvenile stages. We provide a detailed external anatomy of one species, Gnathia aureamaculosa, that has been used extensively in recent ecological studies. Images from scanning electron microscopy of two juvenile instars are compared with two other species, and the literature surveyed to illustrate a range of taxonomically useful traits. The expansion cuticle of the pereion shows how gnathiids are able to expand enormously during a blood meal and also lends caution on using total body length for comparative purposes. A range of morphometric and categorical features are available on the non-expandable sections of the body, such as the head, pleotelson and uropods. Of the three species illustrated, the shape of the eyes and head, and the shape and setation of the pleotelson uropods are diagnostically useful. Evidence from the literature shows that the free-living juveniles are not mancas; the manca instars are passed during the internal developmental period. Anatomical observations cast doubt on the classification of Gnathiidae as Cymothoida, in agreement with recent phylogenetic studies.

Andhracoides shabuddin gen. nov., sp. nov., a new phreatoicidean isopod (Crustacea, Hypsimetopidae) from hypogean aquatic habitats in Andhra Pradesh, India

A decade-long survey of ground waters in the state of Andhra Pradesh, India, has so far yielded over sixty new crustacean taxa, belonging to Copepoda, Bathynellacea, Amphipoda, Isopoda, and Ostracoda. This paper describes a new genus and species attributable to the phreatoicidean isopod family Hypsimetopidae Nicholls, and provides ecological and behavioural observations. The new taxon was found in Guthikonda Cave, which is about 8 km from Piduguralla town in the Palnadu area of Andhra Pradesh State. The species belonging to this clade are unusual in that their dorsoventrally flattened pleotelson gives them a non-phreatoicidean appearance. Because the postanal margin is missing, as in other members of the Hypsimetopidae, this is a superficial similarity rather than homology with other isopods. Other unusual features include robust blunt denticles on opposing margins of the pleotelson and protopod of the uropods. The species in this clade, of which Andhracoides shabuddin gen. nov., sp. nov. is only the first to be described, are related to Nichollsia Chopra & Tiwari, found in northeastern India, and to Pilbarophreatoicus Knott & Halse from the Pilbara region of Western Australia. The new species differs from its undescribed congeners in being nearly devoid of dorsal setae; other species of Andhracoides gen. nov. are much more hirsute.

New genera and species of the marine isopod family Serolidae (Crustacea, Sphaeromatidea) from the southwestern Pacific

The marine isopod family Serolidae is reviewed for the oceanic regions of the tropical and subtropical southwestern Pacific, namely from off Lord Howe Island, Norfolk Island, northern Coral Sea, New Caledonia and Fiji. Two new genera are established: Sedorolis gen. n., monotypic, from New Caledonia and Myopiarolis gen. n., a widespread Southern Hemisphere genus with 11 (eight described) species. The following new species are described: Heteroserolis pellucida (New Caledonia), Sedorolis simplex (New Caledonia), Myopiarolis koro (Fiji), M. systir (New Caledonia), M. norfanz (Lord Howe Plateau and off Norfolk Island), M. lippa (northern Coral Sea), and Thysanoserolis orbicula (New Caledonia). Keys are provided to the serolid genera and the species of Myopiarolis from the southwestern Pacific. The genus Caecoserolis Wagele, 1994 is redefined and restricted to the type species.

Biodiversity of an unknown Antarctic Sea: assessing isopod richness and abundance in the first benthic survey of the Amundsen continental shelf

Concerted efforts are being made to understand the current and past processes that have shaped Antarctic biodiversity. However, high rates of new species discoveries, sampling patchiness and bias make estimation of biodiversity there difficult. Antarctic continental shelf benthos is better studied in the Ross, Weddell and Scotia seas, whilst the Amundsen Sea has remained biologically unexplored largely because of severe ice conditions year-round. Here we report results from examination of the first benthic biological samples taken from the Amundsen Sea. We compare relative abundance, taxonomic richness and faunal composition of isopod families, and genera and species within two example families (i.e. Desmosomatidae and Nannoniscidae) from the Amundsen Sea with complementary sampling from the Scotia Sea. Benthic samples were taken from inner and outer Pine Island Bay (eastern Amundsen Sea) sites using an epibenthic sledge at 500 m. Similar samples were also collected from 15 Scotia arc sites at 160- to 500-m depths. The relative abundance of isopods in the Amundsen Sea samples was high and surprisingly less variable than across samples in the Scotia Sea. The abundance structure of isopods at family level was compared across different Antarctic seas. We found that in the Amundsen, Scotia and Ross Seas two families dominated abundance. In contrast, isopod abundance reported in the literature from Weddell Sea samples was much more evenly distributed across families. The Amundsen continental shelf isopod fauna appears to be rich, with 96% of individuals belonging to currently undescribed species. Most of the genera have either been described or found elsewhere, but for many of these genera it is the first time they have been recorded away from the Antarctic continental slope or deep sea. The Amundsen Sea assemblages differed greatly from the Scotia Sea sites in terms of both composition and (species and generic) richness. This was largely due to high consistency between samples compared with the highly variable Scotia Sea samples. Thorough biological analyses implementing well-structured geographic sampling regimes and the application of phylogeographic analyses on a variety of taxa are required to further explore the geographic structure of biodiversity and the evolutionary history of the Amundsen Sea.

Local and regional species diversity of benthic Isopoda (Crustacea) in the deep Gulf of Mexico

Abstract Recent studies of deep-sea faunas considered the influence of mid-domain models in the distribution of species diversity and richness with depth. In this paper, I show that separating local diversity from regional species richness in benthic isopods clarifies mid-domain effects in the distribution of isopods in the Gulf of Mexico. Deviations from the randomised implied species ranges can be informative to understanding general patterns within the Gulf of Mexico. The isopods from the GoMB study contained 135 species, with a total of 156 species including those from an earlier study. More than 60 species may be new to science. Most families of deep-sea isopods (suborder Asellota) were present, although some were extremely rare. The isopod family Desmosomatidae dominated the samples, and one species of Macrostylis (Macrostylidae) was found in many samples. Species richness for samples pooled within sites ranged from 1 to 52 species. Because species in pooled samples were highly correlated with individuals, species diversity was compared across sites using the expected species estimator ( n =15 individuals, ES 15 ). Six depth transects had idiosyncratic patterns of ES 15 , and transects with the greatest short-range variation in topography, such as basins and canyons, had the greatest short-range disparity. Basins on the deep slope did not have a consistent influence (i.e., relatively higher or lower than surrounding areas) on the comparative species diversity. ES 15 of all transects together showed a weak mid-domain effect, peaking around 1200–1500 m, with low values at the shallowest and deepest samples (Sigsbee Abyssal Plain); no longitudinal (east–west) pattern was found. The regional species pool was analyzed by summing the implied ranges of all species. The species ranges in aggregate did not have significant patterns across longitudes, and many species had broad depth ranges, suggesting that the isopod fauna of the Gulf of Mexico is well dispersed. The summed ranges, as expected, had strong mid-domain patterns, contrasting with the local species richness estimates. The longitudinal ranges closely matched a randomized pattern (species ranges placed randomly, 1000 iterations), with significant deviations in the east attributable to lower sampling effort. The depth pattern, however, deviated from the mid-domain model, with a bimodal peak displaced nearly 500 m shallower than the mode of the randomized distribution. The deviations from random expectation were significantly positive above 1600 m and negative below 2000 m, with the result that regional species richness peaked between 800 and 1200 m, and decreased rapidly at deeper depths. The highest species richness intervals corresponded to the number of individuals collected. Residuals from a regression of the deviations on individual numbers, however, still deviated from the randomized pattern. In this declining depth-diversity pattern, the Gulf of Mexico resembles other partially enclosed basins, such as the Norwegian Sea, known to have suffered geologically recent extinction events. This displaced diversity pattern and broad depth ranges implicate ongoing re-colonization of the deeper parts of the Gulf of Mexico. The Sigsbee Abyssal Plain sites could be depauperate for historical reasons (e.g., one or more extinction events) rather than ongoing ecological reasons (e.g., low food supply).

Diversity and zoogeography of Antarctic deep-sea Munnopsidae (Crustacea, Isopoda, Asellota)

The family Munnopsidae was the most abundant and diverse among 22 isopod families collected by the ANDEEP deepsea expeditions in 2002 and 2005 in the Atlantic sector of the Southern Ocean. A total of 219 species from 31 genera and eight subfamilies were analysed. Only 20% species were known to science, and 11% of these were reported outside the ANDEEP area mainly from other parts of the SO or the South Atlantic deep sea. One hundred and five species (50%) were rare, occurring at only 1 or 2 stations. Seventy-two percent of all munnopsid specimens belong to the most numerous 25 species with a total abundance of more than 75 specimens; 5 of these species (40% of all specimens) belong to the main genera of the world munnopsid fauna, Eurycope, Disconectes, Betamorpha, and Ilyarachna. About half of all munnopsid specimens and 34% of all species belong to the subfamily Eurycopinae, which is followed in occurrence by the Lipomerinae (19%). Munnopsinae is the poorest represented subfamily (1.5%). The composition of the subfamilies for the munnopsid fauna of the ANDEEP area differs from that of northern faunas. Lipomerinae show a lower percentage (7%) in the North Atlantic and are absent in the Arctic and in the North Pacific. This subfamily is considered as young and having a centre of origin and diversification in the Southern Ocean. The analyses of the taxonomic diversity and the distribution of Antarctic munnopsids and the distribution of the world fauna of all genera of the family revealed that species richness and diversity of the genera are highest in the ANDEEP area. The investigated fauna is characterised also by high percentage of endemic species, the highest richness and diversity of the main munnopsid genera and subfamily Lipomerinae. This supports the hypothesis that the Atlantic sector of SO deep sea may be considered as the main contemporary centre of diversification of the Munnopsidae. It might serve as a diversity pump of species of the Munnopsidae to more northern Atlantic areas via the deep water originating in the Weddell Sea. r 2007 Elsevier Ltd. All rights reserved.

Hadromastax dinamoraze sp. nov., the first occurrence of the family Hadromastacidae Bruce and Müller, 1991 (Isopoda, Crustacea, Limnoriidea) in the Indian Ocean

The isopod family Hadromastacidae Bruce and Müller, 1991 is recorded from the Indian Ocean for the first time. Hadromastax dinamoraze sp. nov., the third species in the genus, is described from the Mascarene Island of Rodrigues, Republic of Mauritius, in the western Indian Ocean, where it has been found to occur widely on coral-reef habitats from the intertidal reef flat to the reef slope to depths of about 18 m.