Leptopalaemon gagadjui gen. nov., sp. nov., a new freshwater palaemonid shrimp from Arnhem land,and a re-evaluation of Palaemonetes holthuisi Strenth,with the designation of a new genus,Calathaemon

A new palaemonid shrimp, Leptopalaemon gagadjui, gen. nov., sp. nov., from the Arnhem Land plateau, Australia, is described and illustrated, and its systematic position discussed. The new genus most closely resembles Leptocarpus Holthuis, 1950, presently known only from India. Palaemonetes holthuisi Strenth is re-examined and excluded from the genus Palaemonetes. A new genus, Calathaemon, is designated for its accommodation.     

A report on some pontoniinid shrimps collected from the Seychelle Islands by the F.R.V. Manihine, 1972, with a review of the Seychelles pontoniinid shrimp fauna

A collection of pontoniinid shrimps, principally from the Islands of Mahé and Praslin, in the western Indian Ocean, is described. Twenty-four species were collected, including two new species, Periclimenes difficilis and Periclimenaeus manihinei. Twenty-two species are considered to be commensals and the hosts of many are identified. The early juvenile stages of several species were collected and are described for the first time. The incidence of regeneration in the second pereiopods is studied in detail in Coralliocaris graminea. The pontoniinid shrimp fauna of the Seychelle Islands is reveiwed and its geographic distribution summarized. Two of the species reported are new records for the Indian Ocean and eight are newly added to the Seychelles fauna.     

Kakaducaris glabra gen. nov., sp. nov., a new freshwater shrimp from the Kakadu National Park,Northern Territory,Australia, Crustacea: Decapoda: Palaemonidae with the designation of a new subfamily Kakaducaridinae

A new species of palaemonid shrimp from the Northern Territory Kakadu National Park is described and illustrated. Kakaducaris glabra, gen, nov., sp. nov., can not be satisfactorily referred to the described subfamilies of the Palaemonidae and a new subfamily Kakaducaridinae is designated (see addendum).     

Survey of protozoan, helminth and viral infections in shrimp Litopenaeus setiferus and prawn Macrobrachium acanthurus native to the Jamapa River region, Mexico

We surveyed protozoan and metazoan parasites as well as white spot syndrome virus (WSSV) and infectious hypodermal hematopoietic necrosis virus (IHHNV) in white shrimp Litopenaeus setiferus and the palaemonid prawn Macrobrachium acanthurus native to the lower Jamapa River region of Veracruz, Mexico. The presence of parasites and the infection parameters were evaluated in 113 palaemonid prawns collected during the northwind (n = 45), rainy (n = 38) and dry seasons (n = 30) between October 2007 and July 2008, and in 91 shrimp collected in the rainy season between May and June 2008. In L. setiferus, ciliates of the subclass Apostomatia (Ascophrys sp.) were evident in gills, and third-stage larvae of the nematode Physocephalus sexalatus were evident in the stomach. Cestodes of the genus Prochristianella were evident in the hepatopancreas, while some gregarines of the genus Nematopsis, as well as unidentified larval cestodes, were observed in the intestine. Histology identified Ascophrys sp. in association with gill necrosis and tissue melanization. Slight inflammation was observed in intestinal epithelium near cestode larvae. In M. acanthurus, epibionts of the protozoans Epistylis sp., Acineta sp. and Lagenophrys sp. were observed under uropods, periopods and pleopods. An unidentified ciliate of the Apostomatia was also found in the gills, and Nematopsis was identified in the intestine. No histopathology was observed in association with these parasites. Moreover, neither WSSV nor IHHNV were detected by the polymerase chain reaction (PCR) in any of the L. setiferus or M. acanthurus analysed.     

Experimental infections reveal that common Thai crustaceans are potential carriers for spread of exotic Taura syndrome virus

Taura syndrome virus (TSV) was first reported as a serious cause of shrimp mortality limited to reared Penaeus (Litopenaeus) vannamei in the Americas, where it spread principally through regional and international transfer of live post larvae (PL) and broodstock. Subsequently, through importation of infected broodstock, TSV outbreaks spread to Asia, first to Taiwan and China and then to Thailand, Indonesia and Korea. Since its introduction to Thailand, outbreaks have occasionally been reported from rearing ponds stocked with batches of specific pathogen free (SPF) P. vannamei PL that tested negative for TSV by nested RT-PCR assay. Since it was possible that the outbreaks may have occurred via horizontal transfer of TSV from wild carrier species, we tested 5 common native crustaceans that live in and around shrimp ponds (2 palaemonid shrimp species, Palaemon styliferus and Macrobrachium lanchesteri, and 3 species of crabs, Sesarma mederi, Scylla serrata and Uca vocans) for susceptibility to TSV in experimental challenges. We found that U. vocans, S. serrata and S. mederi did not die but, respectively, gave strong RT-PCR reactions indicating heavy viral load at 5, 10 and 15 d post-injection of TSV and 10, 15 and up to 50 d after feeding with TSV-infected P. vannamei carcasses. Also after feeding, P. styliferus did not die, but a high proportion gave strong RT-PCR reactions at 5 d post-challenge and no reactions at 15 d. Similarly after feeding, M. lanchesteri showed no mortality and gave only light RT-PCR reactions at 2 d, moderate reactions at 5 d and no reaction at 15 d. By contrast, transmission experiments from the TSV-infected crabs and palaemonid shrimp via water or feeding resulted in death of all the exposed P. vannamei from 8 to 12 d post-challenge and all were positive for heavy viral load by RT-PCR assay. Despite the results of these laboratory challenge tests, natural TSV infections were not detected by nested RT-PCR in samples of these species taken from the wild. These results indicated that transmission of TSV from infected crabs and palaemonid shrimp via water or feeding might pose a potential risk to shrimp aquaculture.     

Differences in susceptibility of palaemonid shrimp species to yellow head virus (YHV) infection

Five species of palaemonid shrimp, Macrobrachium rosenbergii, M. lanchesteri, M. sintangense, Palaemon styliferus and P. serrifer, were collected from Penaeus monodon farming areas in Thailand. Some of each species were artificially infected with yellow head virus (YHV) by injection and then monitored by RT-PCR and by immunohistochemistry using monoclonal antibodies specific to 116 kDa, 64 kDa, and 20 kDa proteins of YHV. Natural YHV infections were not detected in any of the shrimp examined. In YHV injection experiments, a high proportion of P. serrifer, P. styliferus and M. sintangense exhibited mild to moderate YHV infections at 3 d post-injection. The severity of infection was reduced in shrimp that survived to 10 and 30 d post-injection. Using immunohistochemistry and RT-PCR, a small proportion of M. lanchesteri showed very mild YHV infections at Day 3 but no infections at Days 10 and 30. No YHV infections resulted in M. rosenbergii. The evidence suggested that M. sintangense, P. styliferus and P. serrifer are susceptible to YHV and carry it for some time. In contrast, M, rosenbergii and M. lanchesteri appear to resist YHV infection and eliminate YHV efficiently. Because they display a range of responses to YHV, palaemonid shrimp may serve as a good model for studying YHV defense mechanisms in shrimp.     

These squatters are not innocent: the evidence of parasitism in sponge-inhabiting shrimps

Marine sponges are frequently inhabited by a wide range of associated invertebrates, including caridean shrimps. Symbiotic shrimps are often considered to be commensals; however, in most cases, the relationship with sponge hosts remains unclear. Here we demonstrate that sponge-inhabiting shrimps are often parasites adapted to consumption of sponge tissues. First, we provide detailed examination of morphology and stomach contents of Typton carneus (Decapoda: Palaemonidae: Pontoniinae), a West Atlantic tropical shrimp living in fire sponges of the genus Tedania. Remarkable shear-like claws of T. carneus show evidence of intensive shearing, likely the result of crushing siliceous sponge spicules. Examination of stomach contents revealed that the host sponge tissue is a major source of food for T. carneus. A parasitic mode of life is also reflected in adaptations of mouth appendages, in the reproduction strategy, and in apparent sequestration of host pigments by shrimp. Consistent results were obtained also for congeneric species T. distinctus (Western Atlantic) and T. spongicola (Mediterranean). The distribution of shrimps among sponge hosts (mostly solitary individuals or heterosexual pairs) suggests that Typton shrimps actively prevent colonisation of their sponge by additional conspecifics, thus protecting their resource and reducing the damage to the hosts. We also demonstrate feeding on host tissues by sponge-associated shrimps of the genera Onycocaris, Periclimenaeus, and Thaumastocaris (Pontoniinae) and Synalpheus (Alpheidae). The parasitic mode of life appears to be widely distributed among sponge-inhabiting shrimps. However, it is possible that under some circumstances, the shrimps provide a service to the host sponge by preventing a penetration by potentially more damaging associated animals. The overall nature of interspecific shrimp-sponge relationships thus warrants further investigation.     

Periclimenes speciosus, a new species of anthozoan associated shrimp (Crustacea: Decapoda: Palaemonidae) from southern Japan

A new species of palaemonid shrimp, Periclimenes speciosus sp. nov., is described and illustrated on the basis of 20 specimens collected from warm-temperate and subtropical waters of southern Japan. Periclimenes speciosus belongs to the "P. aesopius species group", and is associated with sea anemones and a scleractinian coral as well as behaving as a fish cleaner. Morphologically, the new species appears closest to P. holthuisi Bruce, 1969, but can be distinguished from P. holthuisi by the form and armature of the cutting edges of dactylus and fixed finger of the second pereiopod. The coloration in life of both species clearly discriminates one species from the other. The taxonomic status of some specimens previously reported as P. holthuisi is briefly discussed.     

A report on a collection of pontoniine shrimps from Madagacar and adjacent seas

A collection of 41 species of pontoniine shrimp form the Madagascar region is reported upon. Most of the material has been collected from the north-west of Madagascar in the vicinity of Nosy Bé. Six new species, belonging to four different genera, are described: Palaemonella crosnieri, Periclimenes lepidus, P. granulimanus, P. perturbans, Periclimenaeus lobiferus and Onycocaris trullata . A key to the species of Onycocaris is also given. Nineteen species are recorded from Madagascar for the first time, and four species, Periclimenes perlucidus, Periclimenaeus djiboutensis, Pontonia sibogae and Coralliocaris viridis are reported for the second time only in the Indo-West Pacific region. Pontonides unciger Calman is considered to be distinct from P. unciger Holthuis and also is recorded for the second time only. The records of pontoniine shrimp previously reported from Madagascar are briefly summarized. A total of 61 species are now known to be represented in the fauna of Madagascar, indicating a diversity almost as rich as the Indonesian region, with 69 species. Une collection de quarante et une espèces de crevettes pontoniine de la région de Madagascar est analysée. La plus grande partie du matériel provient du nord-ouest de Madagascar, dans le voisinage de Nosy Bé. Six espèces nouvelles appartenant à quatre genres différents sont décrites: Palaemonella crosnieri, Periclimenes lepidus, P. granulimanus, P. perturbans, Periclimenaeus lobiferus et Onycocaris trullata. Une clé des espèces du genre Onycocaris est aussi donnée. Dix-neuf espèces sont notées à Madagascar pour la première fois, et quatre espèces ne sont notées que pour la seconde fois dans la region Indo-Pacifique occidentale. Pontonides unciger Calman est consideréêtre distinct de P. unciger Holthuis, 1952, et n'est aussi noté que pour la seconde fois. Les rapports notant l'occurrence de crevettes pontoniines à Madagascar sont rapidement resumés. Un total de soixante-et-une espèces sont maintenant connues dans la faune de Madagascar, indiquant une diversité presque aussi riche que celle de la region Indonesienne, qui possède soixante-neuf espèces.     

Possible significance of variation in the larval development of palaemonid shrimp

Time of metamorphosis and postlarval development were found to be unrelated in the palaemonid shrimp Macrobrachium rosenbergii (de Man). However, in addition to being influenced by environmental factors, the tendency of a particular palaemonid (Palaemonetes spp.) larva to pass through a given number of larval instars may be inheritable. It is suggested that variation in the duration of the planktonic larval phase and the number of larval instars may help to ensure the dispersal of sibling larvae and thus enhances the survival of the parental genotypes. Also, such variation may increase the probability of recruitment to existing parental populations and the likelihood of successful colonization of freshwater environments.     

Occurrence and recent long-distance dispersal of deep-sea hydrothermal vent shrimps

Deep-sea hydrothermal vents and methane seeps are extreme environments that have a high concentration of hydrogen sulphide. However, abundant unique invertebrates including shrimps of the family Bresiliidae have been found in such environments. The bresiliid shrimps are believed to have radiated in the Miocene (less than 20 Myr); however, the period when and the mechanisms by which they dispersed across the hydrothermal vents and cold seeps in oceans worldwide have not been clarified. In the present study, we collected the deep-sea blind shrimp Alvinocaris longirostris from the hydrothermal vent site in the Okinawa Trough and carried out the first investigation of the 18S rRNA gene of a bresiliid shrimp. The phylogenetic analysis revealed that the bresiliid shrimp is situated at an intermediate lineage within the infraorder Caridea and shows monophyly with palaemonid shrimps, which live in shallow sea and freshwater. Furthermore, the mitochondrial cytochrome oxidase I (COI) gene sequences were analysed to determine the phylogenetic relationship with known bresiliid shrimps. A. longirostris of the Okinawa Trough had two haplotypes of the COI gene, one of which was identical to the Alvinocaris sp. of the cold seeps in Sagami Bay. These results indicate that a long-distance dispersal of A. longirostris occurred possibly within the last 100,000 years.     

Flagellar setae of the second antennae in decapod shrimps: sexual dimorphism and possible role in detection of contact sex pheromones

Summary

The antenna 2 (antennal) flagella of decapod shrimps are chemotactile, and their setae are proposed as sensilla involved in recognition of females by males via a contact sex pheromone on the surface of the female. Male recognition of females receptive to mating occurs in many caridean species upon contact of male antennal flagella with the surface of a newly molted parturial female. The hypothesis of sexual dimorphism in the number and kind of setae on the antennal flagella of four caridean and one penaeid shrimp species was tested with setal counts and observations on setal morphology. Unique male antennal setae (“male-specific sensilla”) were not identified in any of the species investigated. However, the abundance of antennal setae was significantly greater in males than in breeding females in the palaemonid carideans Palemonetes pugio and Macrobrachium ohione. In the hippolytid caridean Thor manningi and alpheid caridean Alpheus normanni, no sexual dimorphism in setal abundance was demonstrated. In the penaeoid Rimapenaeus similis, males had a higher abundance of antennal setae than the larger breeding females but so did juvenile females, similar in size to males. The sexual dimorphism in antennal sensilla in the palaemonid species and its absence in A. normanni might be related to their different mating systems, but no such association is suggested for T. manningi and R. similis. Setal morphology suggestive of chemoreceptive function (a terminal pore) was observed in all species.     

Hyalophysa Iwoffi sp.n. from the Fresh-water Shrimp Palaemonetes paludosus and Revision of the Genus Hyalophysa

SYNOPSIS. Hyalophysa Iwoffi sp. n. is described from the shrimp, Palaemonetes paludosus . Its life cycle is like that of other exuviotrophic apostomes. Hyalophysa Iwoffi differs from the type species, H. chattoni , in the details of its infraciliature and the shape of its macronucleus during the trophont stage. Emended diagnoses of the genus, Hyalophysa , and the species, H. chattoni , also are given.     

Phylogenetic relationships and remarkable radiation in Parartemia (Crustacea: Anostraca), the endemic brine shrimp of Australia: evidence from mitochondrial DNA sequences

The Australian continent is notable for the faunal radiations which have occurred in its saline inland waters. The endemic brine shrimp genus Parartemia inhabits many of these habitats. The complex pattern of morphological variation in parartemiids has impeded the establishment of a sound scheme of species relationships. The present study provides an explicit hypothesis of relationships for the genus based on nucleotide sequence data from a segment of mitochondrial DNA coding for the large subunit rRNA gene. Phylogenetic analyses indicated that the eight known species are genetically distinct, and revealed the existence of at least two new species. The molecular data support certain morphology-based relationships among species, but are inconsistent with other hypotheses. There is evidence that most members of the genus arose in a short interval, followed by remarkable genetic divergence. Comparisons of levels of mt DNA sequence divergence between lineages from saline inland waters and freshwaters using representative crustacean groups from Australia that included parartemiids indicated profound differences in rates of evolution, with halophiles exhibiting greater rates of change than their counterparts from freshwaters.     

浙江省温岭海区虾类资源调查

于1999－2001年间对温岭海区虾类进行了调查,调查表明,该海区计有虾24种,分属7科16属。其中,对虾科8种12种;樱虾科1属2种;玻璃虾科1属1种;鼓虾科1属3种;长臂虾科2属3种;藻虾科2属2种;龙虾科1属1种。对该海区的虾类资源作了评价,并提出了资源开发保护的建议。     

Two new species of Bathypalaemonella Balss (Crustacea, Decapoda, Campylonotidae) from the Australian Northwest Shelf

Two new species of shrimp belonging to the campylonotid genus Bathypalaemonella Balss from the Australian Northwest Shelf. R. brevirostris sp.n. and B. pilosipes sp.n., are described and illustrated. constituting the first records of this genus from Australian waters. Present knowledge of the genus is reviewed and the distribution of the known species listed. The two new species can be readily distinguished from the previously described species of Banthypalaemonella by the very characteristic morphologies of the dactyls of their ambulatory pereiopods.     

Recovery of a tropical stream after a harvest-related chlorine poisoning event

1. Harvest‐related poisoning events are common in tropical streams, yet research on stream recovery has largely been limited to temperate streams and generally does not include any measures of ecosystem function, such as leaf breakdown. 2. We assessed recovery of a second‐order, high‐gradient stream draining the Luquillo Experimental Forest, Puerto Rico, 3 months after a chlorine‐bleach poisoning event. The illegal poisoning of freshwater shrimps for harvest caused massive mortality of shrimps and dramatic changes in those ecosystem properties influenced by shrimps. We determined recovery potential using an established recovery index and assessed actual recovery by examining whether the poisoned reach returned to conditions resembling an undisturbed upstream reference reach. 3. Recovery potential was excellent (score = 729 of a possible 729) and can be attributed to nearby sources of organisms for colonisation, the mobility of dominant organisms, unimpaired habitat, rapid flushing and processing of chlorine, and location within a national forest. 4. Actual recovery was substantial. Comparison of the reference reach with the formerly poisoned reach indicated: (1) complete recovery of xiphocaridid and palaemonid shrimp population abundances, shrimp size distributions, leaf breakdown rates, and abundances of oligochaetes and mayflies on leaves, and (2) only small differences in atyid shrimp abundance and community and ecosystem properties influenced by atyid shrimps (standing stocks of epilithic fine inorganic and organic matter, chlorophyll a, and abundances of chironomids and copepods on leaves). 5. There was no detectable pattern between any measured variables and distance downstream from the poisoning. However, shrimp size‐distributions indicated that the observed recovery may represent a source‐sink dynamic, in which the poisoned reach acts as a sink which depletes adult shrimp populations from surrounding undisturbed habitats. Thus, the rapid recovery observed in this study is consistent with results from other field studies of pulse chlorine disturbances, harvest‐related fish poisonings, and recovery of freshwater biotic interactions, but it is unlikely to be sustainable if multiple poisonings deplete adult populations to the extent that juvenile recruitment does not offset adult shrimp mortality.     

Observations on the Host-Symbiont Relationships of Lagenophrys lunatus Imamura*

An epizoic loricate peritrich, Lagenophrys lunatus Imamura, was found in North Carolina, Virginia, and Maryland on the exoskeleton of the palaemonid shrimp, Palaemonetes pugio, P. intermedius, P. vulgaris, P. paludosus, and Macrobrachium ohione. L. lunatus prefers to attach onto or near the appendages of the host where water movement over the exoskeleton is strongest. The symbionts depend for their food on particles of the host's food and phytoplankton swept to them by these water currents. They attach to other areas of the exoskeleton only when the preferred areas are filled. Trophic individuals are stimulated to undergo a special type of division in advance of the molt of the host that results in the evacuation from the old exoskeleton. Conjugation occurs en masse and has only been observed during molting of the host.     

Systematic revision of the genus Aglyptodactylus Boulenger, 1919 (Amphibia: Ranidae), and analysis of its phylogenetic relationships to other Madagascan ranid genera (Tomopterna, Boophis, Mantidactylus, and Mantella)

Recent field studies revealed two new species of the genus Aglyptodactylus (Amphibia: Anura: Ranidae), which was hitherto considered as monotypic and confined to humid eastern Madagascar. Both new species, Aglyptodactylus laticeps sp. n. and Aglyptodactylus securifer sp. n. , occur syntopically in the deciduous dry forest of Kirindy in western Madagascar. In comparison to Aglyptodactylus madagascariensis from eastern rainforests, the new species A. laticeps shows a remarkable morphological divergence, which may be partly due to adaptations to burrowing habits in dry environments. Despite of the morphological differentiation, advertisement calls and osteology indicate that all three species of Aglyptodactylus are closely related. A phylogenetic analysis of the Madagascan ranid genera Aglyptodactylus, Mantella, Mantidactylus, Boophis , and Tomopterna (the latter including species from Madagascar, Africa, and Asia) strongly supports a sister group relationship of Aglyptodactylus with the ranine genus Tomopterna . We therefore transfer Aglyptodactylus from the Rhacophorinae to the Raninae and discuss implications of this rearrangement for ranoid systematics. The existence of the endemic genus Aglyptodactylus in Madagascar as well as its close phylogenetic relationships to Tomopterna confirm that the Raninae were already present on the Madagascan plate before its separation from Africa. The Madagascan Tomopterna labrosa shows several important differences both to Asian and to African species of the genus, and is therefore transferred from the subgenus Sphaerotheca (now restricted to Asia) to a new subgenus Laliostoma subgen. n .     

An island in the stream: Australia's place in the cosmopolitan world of Indo-West Pacific freshwater shrimp (Decapoda: Atyidae: Caridina)

Mitochondrial DNA sequences were used to investigate phylogenetic and biogeographic relationships among Australian freshwater shrimp from the genus Caridina H. Milne Edwards, 1837 (Atyidae) and congeners from potential source populations throughout the Indo-West Pacific region. Numerous Australian taxa have close evolutionary relationships with non-Australian taxa from locations throughout the region, indicating a diverse origin of the Australian freshwater fauna. This implies many colonisations to or from Australia over a long period, and thus highlights the surprising adeptness of freshwater shrimp in dispersal across ocean barriers and the unity of much of the region's freshwater biota. Interestingly, a study on Australia's other main genus of atyid shrimp, Paratya Miers, 1882, inferred only a single colonisation. A number of potential species radiations within Australia were also identified. This agrees with patterns detected for a large number of Australian freshwater taxa, and so implies a vicariant explanation due to the development of colder, dryer climates during the late Miocene/early Pliocene.