Species Of Brachyuran Crabs Research Articles

First record of Macrophthalmus laevis A. Milne Edwards, 1867 (Decapoda: Brachyura: Macrophthalmidae) from India

Brachyuran crab species belonging to family Macrophthalmidae Dana 1851 are mostly found in mangrove and mudflat intertidal area. Six species belonging to sub family Macrophthalminae Dana 1851, genus Macrophthalmus Desmarest, 1823 were reported from different mangrove and mudflat areas of Gujarat state. The present study reports the presence of Macrophthalmus laevis A. Milne Edwards, 1867 for the first time from India. The detailed description of the species is given.

New species of Latreillopsis Henderson, 1888 (Brachyura: Homolidae) andNeopalicus Moosa & Serène, 1981 (Brachyura: Palicidae)from the Hawaiian Islands.

Two new species of brachyuran crabs belonging to Latreillopsis Henderson, 1888 (Homolidae) and Neopalicus Moosa & Serène, 1981 (Palicidae) respectively are described from Maui, Hawai'i. The new species of Latreillopsis is distinguished from its nine congeners by a granular carapace and pereopods, a triangular G1, and by the distinctive ornamentation of its carapace and third maxillipeds; the new species of Neopalicus from its three congeners by the presence of three triangular anterolateral teeth, absence of extensions on the outer margins of the P3 and P4 propodi, dentate inner margins of the P3, P4 dactyli, and absence of ridges on the female abdomen. Also listed is Latreillia metanesa Williams, 1982 (Latreilliidae), recorded for the first time from the archipelago since its description from Albatross material collected in 1902.

Feeding Behaviour and Functional Role of Some Selected Species of Brachyuran Crabs in Nutrient Cycle at Coastal Belt of Midnapore (East), West Bengal, India

Studies on diet varieties and feeding activities of ten species of brachyuran crabs and their contribution in the nutrient cycle at coastal belt of Midnapore (East), West Bengal, India has established the significant roles played by grapsidae crabs Sesarma (Chiromantes) bidens , S. taeniolatum and Metopograpsus maculatus along with other brachyurans viz. Uca acuta acuta , U. lactea annulipes, U. triangularis bengali, Ocypoda macrocera, Dotilla blanfordi, Dotillopsis brevitarsis and Metaplax intermedia. Organic matter especially the mangrove plant litters after being processed by crabs could form the basis of a coprophagous food chain involving small invertebrates, or be re-exported as micro-particulates. Different nutrient contents viz. organic carbon, available phosphorus, available potassium and available nitrogen analyzed from the gut contents, excavated soils and soils surrounding burrows of the studied brachyuran species were found to show seasonal variability’s and also significant differences among different species.

Records of brachyuran crabs from the Pliocene (Piacenzian) of Reggio Emilia (Emilia Romagna, N Italy)

Four species of brachyuran crabs are recorded from the Pliocene (Piacenzian) clays of the Apennine Mountains, all collected in natural gullies around the Castellarano and Monticelli di Quattro Castella, Reggio Emilia (Emilia Romagna, N Italy). These species are already known in the fossil record of Italy, and are assigned to Calappa granulata (Linnaeus, 1758) (Calappidae De Haan, 1833); Chlinocephalus demissifrons Ristori, 1886 (Euryplacidae Stimpson, 1871); Goneplax rhomboides (Linnaeus, 1758) (Goneplacidae MacLeay, 1838); Monodaeus bortolottii Delle Cave, 1988 (Xanthidae MacLeay, 1838). Chlinocephalus demissifrons and Monodaeus bortolottii are reported for the first time from Emilia Romagna.

Impact of the 2004 Sumatran tsunami on the diversity of intertidal brachyuran assemblages of Maavah, Laamu Atoll, Maldives

A 2-year spatio-temporal survey of intertidal brachyuran crabs involving five sites was conducted in the Maavah reef system, Laamu Atoll, Maldives, from April 2001 to March 2003. In December 2004, the sites were hit by the catastrophic Sumatran tsunami. An 8-month-long study was carried in the same five sites after the tsunami, and the data obtained were compared with the pre-impact baseline data. A sand dune formed at the north-eastern side of the island as a result of the tsunami was also included in the post-tsunami study (site 6). Nine brachyuran crab species not recorded during pre-tsunami sampling in the five study sites were collected after the event. Of these, six species were recorded in site 6 during January 2005, and they started to appear in the other sites in the following months. Nine species of crabs collected during the pre-tsunami periods from four sites were not represented in the post-tsunami collections. Abundance, evenness and diversity of the post-tsunami brachyuran communities of sites 1 and 2 exhibited downward trends, and the evenness and diversity of the post-tsunami communities of site 4 exhibited upward trends when compared with pre-tsunami patterns. Multivariate analyses revealed that the tsunami had changed the post-tsunami brachyuran communities of sites 1–4. However, tests revealed that in site 4, the pre-tsunami brachyuran assemblage 1 (2001–2002) differed from pre-tsunami assemblage 2 (2002–2003) and post-tsunami assemblages. The roles of tsunami-transported species and site-specific dominant species in contributing to faunal dissimilarities between the pre- and post-tsunami brachyuran assemblages were found to be patchy. Further studies would reveal whether the population of any newly added species increases or decreases in the long term.

A new genus and species of anchialine Hymenosomatidae (Crustacea, Decapoda, Brachyura) from Samar, Philippines

A new genus and species of brachyuran crab, Samarplax principe (family Hymenosomatidae) is described from an anchialine cave in Samar Island, Philippines. This cavernicolous species lacks rostrum and has degenerated eyes, possesses two small spines at the lateral margin of the carapace, has a proportionally shorter projected merus of the third maxilliped, an almost flat epistome and brush-like setae instead of teeth along the cutting edges of the chelae. The complete loss of visual organs and pigmentation, the long but slender ambulatory legs and large egg size suggest a completely hypogeal lifestyle for this species. This is the first species of Hymenosomatidae recorded from an anchialine cave in the Philippines exhibiting true troglomorphic adaptations.

BIODIVERSITY AND ROLE OF BRACHYURAN CRABS IN LEAF LITTER DECOMPOSITION ON TYPHOON DESTROYED AREAS AT CAN GIO MANGROVE, HCMC

Natural enviroment of the destroyed zone in Can Gio mangrove by Durian typhoon had been serious bioturbation. The researches about the environment of this area and role of organisms are very important for the mangrove regeneration. There are 19 species of Brachyuran crabs belonged to 13 genus, 7 families such as Sesarmidae, Ocypodidae, Varunidae, Oziidae, Grapsidae, Leucosiidae and Camptadriidae. Perisesarma eumolpe is the dominated species and effects mangrove leaf litter decomposition in there. They consumed all of 3 Rhizophora apiculata leaf types and the brown leaf is the most consumed by them. The consumed leaf rate is 5.2% - 24.44% / wet weight leaf on 24 hours. Perisesarma eumolpe is the important link of the nutritional chain in this ecosystem. They help to return the nutrition for sediment, reduce the leaf litter mass which is lost by tide.

Catalog of the anomuran and brachyuran crabs (Crustacea: Decapoda: Anomura, Brachyura) of the Hawaiian Islands

A total of 68 species of anomuran and 284 living species of brachyuran crabs are listed as reliably occurring in the Hawaiian Islands. These figures include 12 species of brachyurans known to have been introduced, but not four species of anomurans and nine brachyurans whose identifications are questionable and two species of anomurans and 14 brachyurans that appear to have been recorded from the islands in error. Five species of anomurans and one brachyuran so far only known from the Midway Islands are included in the total number of Hawaiian species, but not five species of brachyurans only known from Johnston Atoll that are included only for their biogeographical interest. The Hawaiian crab fauna shows a predominance of wide ranging Indo-West Pacific species (41% of Anomura, 58% of Brachyura), some degree of endemicity (37% of Anomura, 14% of Brachyura), but it is much impoverished in terms of total number of species when compared with the crab fauna of the Indo-Malayan Archipelago, regarded as a center of diversification for many marine taxa. Several taxonomic changes are also made: Trapezia neglecta Castro, 2003, is ascertained to be a junior synonym of T. intermedia Miers, 1886, and a lectotype and a paralectotype are selected for Grapsus oceanicus Hombron & Jacquinot, 1846 (Grapsidae).

A comparative analysis of sperm storage and mating strategies in five species of brachyuran crabs

Variation in female sperm storage is explained, in part, by the amount of sperm transferred at mating. Laboratory mating experiments were conducted on Eurypanopeus depressus and Rhithropanopeus harrisii from the Chesapeake Bay and Pachygrapsus transversus from Florida, while mated pairs of Uca beebei and U. terpsichores were collected from mudflats in Panama. All experiments and collections were conducted during the summer of 2006 and 2007. More sperm was transferred to larger than smaller females, and by species with long copulation durations (R. harrisii and E. depressus). These two species live in cryptic habitats, have high sperm/egg ratios, and likely store sperm across multiple broods. In contrast, P. transversus and U. beebei mate conspicuously, have short copulations, transfer fewer sperm, and have low sperm/egg ratios. Comparisons of sperm transfer across different mating strategies and habitats provide a better understanding of female sperm storage in the Brachyura.

Predicting diet and consumption rate differences between and within species using gut ecomorphology

1. Rapid environmental changes and pressing human needs to forecast the consequences of environmental change are increasingly driving ecology to become a predictive science. The need for effective prediction requires both the development of new tools and the refocusing of existing tools that may have previously been used primarily for purposes other than prediction. One such tool that historically has been more descriptive in nature is ecomorphology (the study of relationships between ecological roles and morphological adaptations of species and individuals). 2. Here, we examine relationships between diet and gut morphology for 15 species of brachyuran crabs, a group of pervasive and highly successful consumers for which trophic predictions would be highly valuable. 3. We show that patterns in crab stomach volume closely match some predictions of metabolic theory and demonstrate that individual diet differences and associated morphological variation reflect, at least in some instances, individual choice or diet specialization. 4. We then present examples of how stomach volume can be used to predict both the per cent herbivory of brachyuran crabs and the relative consumption rates of individual crabs.

First record of marine crab, Eucrate alcocki Serène, in Serène and Lohavanijaya, 1973 (Crustacea, Decapoda, Brachyura, Euryplacidae) from India

This paper reports the occurrence of a marine brachyuran crab species Eucrate alcocki Serene, in Serene et al., 1973, of the family Euryplacidae Stimpson, 1871, for first time from India, based on a male specimen from Parangipettai fish landing centre in Bay of Bengal, Southeast Coast of India. Although morphologically corresponding with what is currently defined as E. alcocki, the color pattern of the carapace of the present specimen is rather different from that of the Chinese material-only the anterior fifth of the carapace is marked with scattered red spots, the rest of the surface is yellowish, with four unusually shaped red blotches which almost look like Sanskrit characters.

Molecular cloning of the crustacean hyperglycemic hormone (CHH) precursor from the X-organ and the identification of the neuropeptide from sinus gland of the Alaskan Tanner crab, Chionoecetes bairdi

Crustacean hyperglycemic hormone (CHH) secreted from sinus glands primarily elicits hyperglycaemia in crustaceans. CHH is particularly important for energy metabolism during environmental and physiological stress as animals switch to anaerobiosis. CHH has been purified from multiple brachyuran crab species to date, but not from the cold water Tanner crab, Chionoecetes bairdi, a species found in Alaskan coastal waters. The purpose of molecular cloning the C. bairdiCHH precursor and identification of its neuropeptide form in sinus glands is to establish tools to further study cold water crab metabolic physiology. Cold water crabs such as those in the genus Chionoecetes are a good model for understanding the role that climate change and associated water temperature changes might have on metabolic physiology. CHHs in sinus glands of C. bairdi were purified using reverse-phase HPLC and were identified as CHH with an enzyme-linked immunosorbent assay (ELISA) using cross-reacting Callinectes sapidus and Carcinus maenas CHH antisera. The bioactivity of CHH was further assessed using a homologous assay by injecting CHH into eyestalk ablated C. bairdi and measuring subsequent rise in circulating glucose. The full length cDNA (1944bp) of C. bairdiCHH was determined by PCR using degenerate primers cloning and 5′, 3′ rapid amplification of cDNA ends (RACE). A phylogenetic analysis of deduced amino acid sequences from six brachyuran crab species showed C. bairdi CHH most closely related to the majid crab, Libinia emarginata (P55688). Future studies will enable us to compare metabolic physiology and requirements of cold water C. bairdi with the warm water crab C. sapidus.

Checklist of the marine and estuarine Brachyura (Crustacea: Decapoda) of northern and northeastern Brazil

A total of 272 species of brachyuran crabs are reported from marine and estuarine environments in northern and northeast Brazil. The checklist is derived from the literature published from 1847 to 2008, and includes all species that have been reported at least once from the study area. It is also partially supported by material deposited in the crustacean collection of the Departamento de Oceanografia, Universidade Federal de Pernambuco, city of Recife, Brazil (DOUFPE). The families containing the highest number of species in northern and northeastern Brazil are Majidae (31), Portunidae (22), Epialtidae (20), Panopeidae (20), and Xanthidae (18). The remaining species are distributed in 39 families. The analysis of the distribution of the species in the region, allows for identification of four patterns of longitudinal distribution (western Atlantic, Amphi-Atlantic, Amphi-American, and circumtropical species) and, in the western Atlantic, six patterns of latitudinal distribution (Virginian, Carolinian, Antillean, Central-South American, Boreal, and Endemic). Two non-indigenous species have also been reported. Most of the species represented in northern and northeastern Brazil have Antillean (94 species; 34.5%) and Carolinian (75 species; 27.6%) pattern of distribution.

Specialized shell-breaking crab claws in Cretaceous seas

Here we report on a large brachyuran crab species from the Late Cretaceous of Mexico that has claws indicative of highly specialized shell-breaking behaviour. This crab possessed dimorphic claws (the right larger than the left), armed with several broad teeth, including a curved tooth structure found at the base of the movable finger of the right claw. The curved tooth is similar to the one observed on claws of many living durophagous crabs that use it as a weapon to peel, crush or chip the edges of hard-shelled prey, particularly molluscs. These morphological traits suggest that specialized shell-breaking crab predators had evolved during the Cretaceous, which contradicts previous findings supporting an Early Cenozoic origin for specialized shell crushers within the brachyuran clade.

Extensão da distribuição geográfica de alguns decápodos braquiúros e porcelanídeos (Crustacea) para a costa do Estado de São Paulo, Brasil

Investigations of the distribution of marine organisms provide a better understanding of the patterns of distribution and dispersal of these animals. Extensions of the distributional limits of decapod crustaceans in Brazilian waters have been recorded steadily and gradually, but these limits still remain poorly understood. The present study provides information extending the known range of eight species of brachyuran crabs and one species of porcellanid crab. The animals were obtained by Scuba diving during a sampling program carried out near Vitoria Island, Ilhabela, on the northeastern coast of the State of Sao Paulo (23o44’04”S-45o01’35”W) between February, 2004 and January, 2005. These new records extend the geographical distributions of the porcellanid Petrolisthes amoenus (Guerin Meneville, 1855), the majoids Mithrax caribbaeus Rathbun, 1920, Mithrax verrucosus H. Milne Edwards, 1832 , Nemausa acuticornis (Stimpson, 1871) and Teleophrys ornatus Rathbun, 1901, and the xanthoids Domecia acanthophora acanthophora (Desbonne & Schramm, 1867), Garthiope spinipes (A. Milne Edwards, 1880), Xanthodius denticulatus (White, 1847) and Xanthodius parvulus (Fabricius, 1793) to the Sao Paulo coast. These new records may be related to different mechanisms of larval dispersal, larval transport by ballast water, or may simply be exceptional records.

Extension of the geographical distribution of some brachyuran and porcellanid decapods (Crustacea) to the coast of the State of São Paulo, Brazil

Investigations of the distribution of marine organisms provide a better understanding of the patterns of distribution and dispersal of these animals. Extensions of the distributional limits of decapod crustaceans in Brazilian waters have been recorded steadily and gradually, but these limits still remain poorly understood. The present study provides information extending the known range of eight species of brachyuran crabs and one species of porcellanid crab. The animals were obtained by Scuba diving during a sampling program carried out near Vitória Island, Ilhabela, on the northeastern coast of the State of São Paulo (23º44'04"S-45º01'35"W) between February, 2004 and January, 2005. These new records extend the geographical distributions of the porcellanid Petrolisthes amoenus (Guérin Menéville, 1855), the majoids Mithrax caribbaeus Rathbun, 1920, Mithrax verrucosus H. Milne Edwards, 1832, Nemausa acuticornis (Stimpson, 1871) and Teleophrys ornatus Rathbun, 1901, and the xanthoids Domecia acanthophora acanthophora (Desbonne & Schramm, 1867), Garthiope spinipes (A. Milne Edwards, 1880), Xanthodius denticulatus (White, 1847) and Xanthodius parvulus (Fabricius, 1793) to the São Paulo coast. These new records may be related to different mechanisms of larval dispersal, larval transport by ballast water, or may simply be exceptional records.

Effects of temporary food limitation on survival and development of brachyuran crab larvae

As a consequence of the combined effects of prey patchiness and diel or tidal vertical migrations in the water column, decapod crustacean larvae may experience temporal or spatial variability in the availability of planktonic food. In a laboratory study, we evaluated effects of temporarily limited access to prey on the larvae of three species of brachyuran crabs, Chasmagnathus granulata, Cancer pagurus and Carcinus maenas. Stage-I zoeae were fed ad libitum for 4 or 6 h per day (20 or 25% treatments; 6 h tested in C. pagurus only), and rates of larval survival and development were compared with those observed in continuously fed control groups (24 h, 100%). In C. granulata, we also tested if intraspecific variability in initial biomass of freshly hatched larvae originating from different broods has an influence onearly larval tolerance offood limitation.Moreover,weexposedembryosandlarvae of this estuarine species to moderately decreased salinities to identify possible interactions of osmotic and nutritional stress. Finally, we evaluated in this species the effect of food limitation on survival from hatching through all larval instars to metamorphosis. In all three species, limited access to prey had only weak or insignificant negative effects on survival through the Zoea-I stage. The strength of the effects of temporary food limitation varied in C. granulata significantly among broods. However, no significant relationships were found between initial larval biomass (C content) and either survival or development duration. Strongly decreased survival to metamorphosis was found when food limitation continued throughout larval development. Thus, early brachyuran crab larvae are well adapted to transitory lack of planktonic food. The capability of the Zoea-I stage of C. granulata to withstand nutritional stress also under conditions of concomitant salinity stress allows them to exploit various brackish environments within estuarine gradients. However, continued exposure to limited access to planktonic prey may exceed the nutritional flexibility of C. granulata larvae.

New records of 31 species of brachyuran crabs from the joint Taiwan-France expeditions, "Taiwan 2000" and "Taiwan 2001", off deep waters in Taiwan

[In recent collections from deep waters around Taiwan, numerous new records of brachyuran crabs were obtained for Taiwan. Thirty-one species are added to the known Taiwanese brachyuran fauna, including 13 new records of genera and two new records of families (Homolodromiidae and Cymonomidae). The established brachyuran crab fauna for Taiwan now stands at 604 species. Au cours de collectes recentes dans les eaux profondes autour de Taiwan, de nombreux signalements nouveaux de crabes Brachyoures ont ete obtenus. Trente et une especes sont ainsi ajoutees a la faune connue des Brachyoures de Taiwan, incluant 13 nouvelles citations de genres et deux nouvelles citations de familles (Homolodromiidae et Cymonomidae). La faune des Brachyoures de Taiwan s'eleve maintenant a 604 especes., In recent collections from deep waters around Taiwan, numerous new records of brachyuran crabs were obtained for Taiwan. Thirty-one species are added to the known Taiwanese brachyuran fauna, including 13 new records of genera and two new records of families (Homolodromiidae and Cymonomidae). The established brachyuran crab fauna for Taiwan now stands at 604 species. Au cours de collectes recentes dans les eaux profondes autour de Taiwan, de nombreux signalements nouveaux de crabes Brachyoures ont ete obtenus. Trente et une especes sont ainsi ajoutees a la faune connue des Brachyoures de Taiwan, incluant 13 nouvelles citations de genres et deux nouvelles citations de familles (Homolodromiidae et Cymonomidae). La faune des Brachyoures de Taiwan s'eleve maintenant a 604 especes.]

Gonopod tegumental glands: a new accessory sex gland in the Brachyura

It is not yet known whether gonopod tegumental glands (GTG) previously described in one species of brachyuran crab (Chionoecetes opilio) are a general feature in this large taxon. In order to determine the prevalence and role of GTG in the Brachyura, the first gonopods of six species of boreo-temperate and tropical brachyurans belonging to four families were examined morphologically and histologically, using the PAS–Alcian-blue staining protocol: Carcinus maenas, Portunus sebae, and Ovalipes ocellatus (Portunidae), Cancer irroratus (Cancridae), Grapsus grapsus (Grapsidae), and Petrolisthes armatus (Porcellanidae). Discrete rosette-type GTG were found in all species examined, although the longitudinal extent and location differed somewhat between taxa. The GTG were invariably grouped about the ejaculatory canal, and communicated with the lumen of the ejaculatory canal via ducts which traversed pores in the cuticle; staining properties of secretions at the duct openings to the ejaculatory canal matched those of the GTG. Neither GTG, ducts, nor pores were observed in regions distal to the ejaculatory canal. These data indicate that the prime, if not exclusive, role of the GTG is in reproduction, and that GTG may therefore be considered accessory sex glands. Together with previous and current investigations such GTG have been observed in all eight brachyuran species examined from five families, and are thus probably ubiquitous within the Brachyura. The organization and nature of the gland secretions differed between taxa: alternating acid (AMPS) and neutral mucopolysaccharide (NMPS) layers in the three Portunidae, AMPS only in Cancer irroratus, and NMPS only in Grapsus grapsus and Petrolisthes armatus. When combined with data on gonopod morphology and occurrence of spermatophore-less sealant in the ejaculate of various brachyurans, two plausible functions of the AMPS GTG secretions emerge: protection of the male's genetic investment (stored spermatophores) from opportunistic microbes following copulation, and the reciprocal processes of sperm competition and paternity assurance. The NMPS secretions may function as a lubricant to reduce mechanical wear of the ejaculatory canal by the second gonopod during copulation, and to reduce the viscosity of the ejaculate from the vas deferens as it enters the narrow ejaculatory canal.

Rhizocephalans (Crustacea: Cirripedia) from Taiwan

One species of shrimp and sixteen species of brachyuran crabs are parasitized by rhizocephalans in Taiwanese waters. Ten of the crabs have never before been recorded as hosts of rhizocephalans. Eight species of rhizocephalans occur in Taiwan. Four species, Diplothylacus taiwanensis, D. calappae, Sacculina scutigera and S. docleae are new to science. The paper records the first example of simultaneous infection of the same host individual by two rhizocephalan species, and provides further evidence of successive moulting of the external mantle cuticle in several species of sacculinids.