Desmosomatidae and Nannoniscidae (Crustacea,Isopoda, Asellota) from bathyal and abyssal depths off North Carolina and their evolution

The deep-sea asellote isopod (Crustacea) species, belonging to the families Desmosomatidae and Nannoniscidae, were studied from R/V Eastward collections of Duke University from three study sites off North Carolina. The Desmosomatid isopod Eugerda svavarssonni n. sp. is described from Site Alpha at 620m. Eugerda latipes Hansen, previously known from boreal North Atlantic, is also reported from this upper slope site. Two new desmosomatid isopods, Mirabilicoxa hessleri n. sp. and M. alberti n. sp., and a new nannoniscid isopod Exiliniscus chandravoli n. sp. are also described from site Beta from 2700 to 3700 m. A nannoniscid isopod Leutziniscus jebamoni gen n., n. sp., and a desmosomatid isopod, Prochelator sarsi n. sp., are described from the deepest study site Omega in the Hatteras Abyssal Plain. A new genus, Nannoniscella is erected to accommodate Nannoniscoides bicustatus Siebenaller and Hessler, 1977. This paper also includes discussions on comparative morphology and sexual dimorphism in species of Mirabilicoxa, zoogeography of species of the genus Eugerda and phylogeny with emphasis on the genus Prochelator.     

Seasonal reproduction in deep-sea Crustacea (Isopoda: Asellota)

A collection of Crustacea Isopoda (suborder Asellota) from a 10-year sampling programme in the Rockall Trough, NE Atlantic (54°40′N, 12°15′W) was analysed for evidence of breeding seasonality. No evidence of seasonal activity was found — adults and newly released juveniles were present throughout the year — but there was a strong seasonal pattern for breeding intensity. A significantly higher proportion of females was brooding during the winter months (25%) compared to the summer (5%), and the percentage of females brooding varied significantly with depth. The breeding pattern was synchronized to the seasonal deposition of organic detritus known to occur during the summer in the NE Atlantic. There were more newly released juveniles in samples during the summer than during the winter, with most females appearing to release their young at the time the deposition began. This deposition appears to be a major seasonal factor dominating the life-cycles of most benthic species in the Rockall Trough. Juvenile settlement for a range of taxa (echinoderms, molluscs and crustaceans) occurs while the detritus is present and most species maximize vitellogenesis at this time.     

Two new species of terrestrial Isopoda (Crustacea,Oniscidea) from Ascension Island

A collection of eight species of terrestrial isopods from lava and cave sites on Ascension Island is described. Two species, Niambia longiantennata (Platyarthridae) and Elumoides coecus (Eubelidae), are described as new. Atlantoscia alceui Ferrara and Taiti (Philosciidae) is considered to be a junior synonym of A. floridana (Van Name) and the genus Ocelloscia Schultz and Johnson of Atlantoscia Ferrara and Taiti. At present the oniscidean fauna known from Ascension Island consists of 13 species.     

The Cassidininae Hansen, 1905 (Crustacea: Isopoda: Sphaeromatidae) of Australia

The Cassidininae of Australia are revised. The status of the subfamily is assessed and it is concluded that, as presently constituted, the Cassidininae is an artificial taxon. It is maintained here as a taxon of convenience (sensu lato) until the other sphaeromatid subfamilies can be reassessed, but a new diagnosis (sensu stricto) is given. The genus Cassidina is redescribed. Three new genera are established: Agostodina gen. nov. (type species: A. munta sp. nov.), Apemosphaera gen. nov. (type species: A. naranagi sp. nov.) and Discidina gen. nov. (type species: D. banawarra sp. nov.). New diagnoses are provided for the genera Cassidina Milne Edwards, Chitonopsis Whitelegge, Cassidinidea Hansen, Paracassidina Baker, Syncassidina Baker and Platysphaera Holdich and Harrison. The genus Dies is placed in synonymy with Cassidinidea and an annotated list is given of all species of the genus. The following new species (excluding the new type species) are described: Chitonopsis booyoolie, Agostodina munta, Paracassidina anasilla, P. bakeri, P. bamarook, P. bilbie, P. cervina, P. dama, P. fuscina, P. incompta, P. kutyo, P. munna, P. petala, P. prolata, P. wurrook and Cassidinidea korpie. Keys to the Australian genera and species are given.     

Colanthura,Califanthura, Cruranthura and Cruregens,related genera of the paranthuridae (Crustacea: Isopoda)

Summary

The relationships between the genera Colanthura Richardson, Califanthura Schultz, Cruranthura Thomson and Cruregens Chilton are discussed and presented from a cladistic point of view. Of the 17 species known three are described as new, Colanthura bruscai, Colanthura kensleyi and Califanthura lowryi.     

Postmarsupial development of Atlantoscia floridana (van Name, 1940) (Crustacea,Isopoda, Oniscidea): the manca stages

In this paper we describe the postmarsupial development of the manca stages of Atlantoscia floridana (van Name, 1940). Ovigerous females were collected in Reserva Biológica do Lami, Porto Alegre, RS, Brazil and separately reared in small containers at 20°C (±1°C). After birth each newborn (manca I) was reared separately in order to observe the subsequent moults. In a period of about 12 h the animals underwent the first moult. The manca II stage lasts 9.16±1.57 days while manca III takes up a period of 9.96±1.05 days. Growth was observed through measurements of cephalothorax width. The three manca stages are described, illustrated and compared with the adults. The main distinguishing characteristics among mancas I, II and III are presented as well as the b/c and d/c co-ordinates of the noduli laterales.     

Association of a juvenile phoretic uropodid mite with the beach hopper Traskorchestia traskiana (Stimpson, 1857) (Crustacea: Talitridae)

A phoretic association of an undescribed uropodid deutonymph (Acari: Uropodidae) with the beach hopper Traskorchestia traskiana (Crustacea: Talitridae) is examined. Only juvenile mites (deutonymphs) were found attached to the coxal gills of the 257 beach hoppers examined. Both prevalence (range = 27·1–75·0%) and mean intensity (range = 1·3–3·7) increased as host size increased, possibly due to increased exposure time to the mites and a greater area for attachment in larger hosts. Among the gills, the mites exhibited a preference for coxal gill 5, which may be due to pH and humidity gradients but did not seem to be influenced by grooming or agitation of the gills by adjacent appendages.     

Larval development of Pandalus gracilis Stimpson (Crustacea: Decapoda: Pandalidae) reared in the laboratory

The complete larval development of Pandalus gracilis Stimpson is described based on larvae reared in the laboratory. The species has four larval stages (stages 1–4) and one postlarval stage (stage 5). The survival rate of the postlarva stage is very high. Of the 40 larvae reared individually, 39 larvae moulted to the postlarva stage within approximately 21 days at a rearing temperature of 15°C. Larval morphological characteristics of the species are described and figured. Larval development of P. gracilis is compared with other Pandalus and Pandalopsis species. Komai (1999 Komai, T. 1999. A revision of the genus Pandalus (Crustacea: Decapoda: Caridea: Pandalidae).. Journal of Natural History, 33: 1256–1372.  [Google Scholar]) divided species of Pandalus into four species groups based on adult morphology. Pandalus gracilis belongs to the P. hypsinotus group. In this study, using larval characters, the P. hypsinotus group can be divided into two groups by the appearance of the mandibular palp and the shape of the telson: the first group contains P. hypsinotus and P. danae, and the second group contains P. gracilis, P. prensor, and P. nipponensis.     

Infestation by the freshwater cymothoid Artystone trysibia Schioedte (Crustacea,Isopoda): parasite and host behaviour

To observe the behaviour of cymothoid isopods during the infestation process, 30 experiments in aquaria were carried out, using the fish Gymnogeophagus gymnogenys (Hensel, 1870) and Jenynsia multidentata (Jenyns, 1842) as hosts, and Artystone trysibia Schioedte, 1866 as the parasite. All the specimens were collected from Guaíba Lake in Porto Alegre, Rio Grande do Sul. We recorded and analysed the behavioural acts of the parasites and hosts from the moment of encounter to the infestation, which was considered to be completed when the parasite had inserted itself into the fish's body. The behavioural acts are shown as a flow diagram, including the frequencies of occurrence of each act. Positive infestation occurred in 60% of the experiments. No relationship was observed between the sizes of the parasite and host, and the success of the infestation.     

Antheluridae,a new family of Crustacea (Isopoda: Anthuridea) with new species from Australia

The Antheluridae is erected for the genera Anthelura Norman and Stebbing, Ananthura Barnard and Anthomuda Schultz. The family is characterized by mouthparts of biting form; maxillipedal endite broad; maxillipedal palp broad, of 4–5 free articles; several posterior carpal and propodal spines on pereopods 2–7; pereopod 7 with transverse anterodistal propodal setal row on mesial face; and single telsonic statocyst. Its relationships to other anthurideans, especially the Paranthuridae, is discussed. Three new Australian species are described, Ananthura billarderia from off New South Wales, Anthomuda chorizema from the southeastern coast, and Anthomuda hovea, from the Great Barrier Reef, Coral Sea islands and Western Australia.

Bathura Schultz, Austranthura Kussakin and Valoranthura Kensley are junior synonyms of Ananthura, and Diaphoranthura is a junior synonym of Anthomuda.     

The distribution and habitat preferences of the Afro-European species of Dynamene (Crustacea: Isopoda)

Summary

The geographical distribution of the genus Dynamene is described in the light of the recent discovery of three new species. D. bidentata appears to have a Boreal distribution whilst that of D. edwardsi and D. magnitorata is Atlanto-Mediterranean. D. torelliae, D. bifida, and D. tubicauda have a Mediterranean distribution but the first species may extend into the Black Sea. Only one species, D. ramuscula, has been recorded outside the Afro-European region, in S.E. Australia. The ranges and habitat preferences of those species outside the Mediterranean overlap as do some of those within the Mediterranean, particularly in the Naples Bay region. Juveniles of D. bidentata inhabit and feed on intertidal algae while adults shelter in crevices and empty tests of Balanus perforatus, mainly below MTL. Settlement of males into barnacle tests appears to be random, but females show some degree of aggregation, perhaps to other females. Other species show the same change of habitat at sexual maturity and all inhabit intertidal or inshore localities.     

Taxonomic revision of the genus Littorophiloscia Hatch, 1947 (Crustacea,Isopoda, Oniscidea) with description of six new species

In the present revision 15 species of Littorophiloscia are recognized. Six species, namely L. tropicalis, L. koreana, L. amphindica, L. pallida, L. bifasciata and L. hawaiiensis are described as new. Littorophiloscia isabellae (Vandel, 1973) is considered to be a junior synonym of L. albicincta (Vandel, 1973), and Philoscia dartevellei Brian, 1953 and Vandeloscia orientalis Roman, 1977 are considered to be junior synonyms of L. culebrae (Moore, 1901). Alloniscus compar sens. Vandel, 1952 nec Budde-Lund, 1893 is considered to be distinct from L. riedli (Strouhal, 1966) and it has been renamed L. tropicalis sp. nov. The genera Bilawrencia Vandel, 1973, Helenoscia Vandel, 1977, Vandeloscia roman, 1977 and Sayoscia Schultz, 1983 are considered to be synonymous with Littorophiloscia. Diagnostic characters of all the species are illustrated. A map and comments on the distribution of the 15 species are included.     

New species and records of Asellota from the Indian Ocean (Crustacea: Peracarida: Isopoda)

In this study of asellote Isopoda from the Indian Ocean, 29 species in 11 genera and seven families are recorded. Twenty-one species are described as new: family Gnathostenetroididae, Maresiella aldabrana ; family Janiridae, Carpias mossambica ; family Joeropsidae, Joeropsis algensis, J. arpedes, J. dimorpha, J. hamatilis, J. lentigo, J. pentagona, J. pleurion ; family Pleurocopidae, Pleurocope wilsoni ; family Pseudojaniridae, Pseudojanira meganesus ; family Santiidae, Santia spicata, S. urospinosa ; family Stenetriidae, Hansenium aldabrae, H. expansa, H. remocarpus ; Mizothenar serratum, Stenetrium assumentum, S. quinquedens, S. zanzibarica, Stenobermuda brucei. The first record of the family Pleurocopidae (Pleurocope wilsoni) and the genus Mizothenar (family Stenetriidae) from the Indian Ocean are included. Diagnoses of the genera and species are provided, and keys to the Indian Ocean species of most of the genera. The material comes primarily from Aldabra Atoll, the granitic Seychelles islands, Zanzibar Island, the Comoro Islands, and Phuket in Thailand. A few samples are from material of the International Indian Ocean Expedition carried out in the mid-1960s.     

New species and records of Flabellifera from the Indian Ocean (Crustacea: Peracarida: Isopoda)

In this study of flabelliferan Isopoda from the Indian Ocean, 19 species are described as new, in 11 genera and two families: family Cirolanidae, Baharilana koloura, B. lira, Cirolana aldabrensis, C. mimulus, C. somalia, C. undata, Eurydice paxilli, and Metacirolana chemola; family Sphaeromatidae, Cassidinidea clarkae, Cymodoce fuscina, C. lirella, Dynamenella alveolata, D. remex, Heterodina (new genus), H. mccaini, Oxinasphaera brucei, O. furcata, O. tetrodon, Paracilicaea stauros, and Sphaeromopsis sulcifera. Diagnoses of the genera and species are provided, and keys to the Indian Ocean species of most of the genera are provided. The material comes primarily from Aldabra Atoll, the granitic Seychelles islands, Zanzibar Island, and Phuket in Thailand. A few miscellaneous samples from the South African Museum collections, and from the International Indian Ocean Expedition carried out in the mid‐1960s are included.     

On the South American species of the genus Meridiosignum (Crustacea: Isopoda: Asellota: Paramunnidae)

Meridiosignum undulatum n. sp. and M. disparitergum n. sp. are described from off the Río de la Plata estuary. These two new species are easily distinguished from other members of the genus Meridiosignum in having the lateral margins of pereonites 2 and 3 bilobed (the concavity is much more pronounced in M. disparitergum), and those of pereonite 4 produced into a single process. The terminal male instar of Meridiosignum menziesi (Winkler, 1994 Winkler, H. 1994. Paramunnidae (Crustacea: Isopoda: Asellota) from the Magellan Strait.. Zool J Linn Soc., 110: 243–296. [Crossref] , [Google Scholar]) is described, and this species is herein reported from the Beagle Channel and Puerto Deseado. All the species currently placed in Meridiosignum were found in shallow waters in the southern hemisphere, M. undulatum n. sp. and M. disparitergum n. sp. being the species recorded at the greatest depth (129 m).     

Considerations about the genus Pentoniscus Richardson, 1913 (Crustacea: Isopoda: Oniscidea) with description of a new species

The status of the neotropical genus Pentoniscus Richardson, 1913 is reconsidered and a diagnosis of this genus is given. It is shown that Pentoniscus Richardson, 1913 is a valid genus and not a synonym of Philoscia Latreille, 1804 as discussed by Schultz (1968). The type species, Pentoniscus pruinosus Richardson, 1913 is redescribed and for the first time figured in detail. A new species of Pentoniscus Richardson, 1913 is described from Costa Rica, Central America, which differs remarkably from its congeners in being unpigmented and blind.