Abstract in English:Abstract Caprellid amphipods are common crustaceans at Sargassum beds of southeastern Brazil and constitute an important link between primary producers and marine consumers. The goal of this study is to evaluate population and reproductive biology of two caprellid species: Paracaprella tenuis Mayer, 1903 and Pseudaeginella montoucheti Quitete, 1971. Sargassum cymosum Agardh, 1820 samples were collected monthly between October 2010 and September 2011 in a rock shore in southeastern Brazil. The caprellids were identified, counted, measured and classified as males, immature females, sexually mature females, ovigerous females and juveniles. Eggs were counted and measured. Higher densities of P. tenuis and P. montoucheti were found mainly in winter and lower densities in fall and summer. Density variation is probably related to organic matter supply and substrate availability. Both species showed continuous reproduction with reproductive peaks. Pseudaeginella montoucheti larger egg volume indicates a longer incubation period. The egg volume was directly related to female size. The number of eggs was weakly related to female size, indicating that fecundity may be driven by other factors, such as the physiological conditions. Sex ratio deviated for males suggests a higher longevity of males. The present study highlighted important data of two caprellids species that occur in algal beds of different regions.
Abstract in English:Abstract Trawls from the Bay of Bengal obtained material of a new species of the goneplacid crab, Carcinoplax mistio, the sixth species of the genus known from India. The new species superficially resembles C. purpurea Rathbun, 1914, and C. sinica Chen, 1984, from the western Pacific. Records of C. sinica from the Persian Gulf are also here referred to the new species. Carcinoplax mistio n. sp. differs from its closest congeners mainly in the form of the carapace, anterolateral armature, proportions of the ambulatory legs and structure of the male pleon.
Abstract in English:Abstract During exploratory trips conducted between August and December 2016, six shrimps, found in association with the crinoid Nemaster grandis A.H. Clark, 1909, ere collected in Chichiriviche de la Costa, Vargas State (Venezuela). A photographic record of the crinoids and the shrimps was conducted in situ. Shrimps were preserved in ethyl alcohol 90% and carried to the Laboratorio de Carcinología de la Universidad de Oriente, Núcleo Nueva Esparta. Once in the laboratory, the shrimps were taxonomically described and sexed. Shrimps were identified as Periclimenes crinoidalis Chace, 1969, constituting the first record of this species in Venezuelan waters. These findings also expand the known distribution range for the crinoid N. grandis in Venezuela, where the species exhibits two morphotypes, one of them not previously described. Additionally, a table with the species of decapods found associated with echinoderms in Venezuela is provided.
Abstract in English:Abstract We aimed to analyze the crustacean bycatch from the Xiphopenaeus kroyeri fishery in the Santa Catarina State and compare the bycatch’s biomass to that of the target species. Shrimp and environmental factors were sampled monthly from July 2010 through June 2011. For each crustacean species, we calculated the number of individuals, the relative abundance and the occurrence frequency. The relative abundance was classified as very abundant (Va), abundant (Ab) or low abundance (La), while the occurrence frequency was labeled continuous (Co), accessory (Ac) or accidental (Ad). We observed a total richness of 28 species, which is considered high for a subtropical region. Brachyura was the most frequent taxon (74%) followed by Penaeiodea (18%). Five species were considered Va (Arenaeus cribrarius, Callinectes danae, C. ornatus, Isochelis sawayai and Pleoticus muelleri), and eight species were considered Co (A. cribrarius, C. danae, C. ornatus, Farfantepenaeus paulensis, Hepatus pudibundus, Libinia spinosa, Litopenaeus schmitti and Sicyonia dorsalis), suggesting that the studied environment is heterogeneous and provides a variety of microhabitats, enabling many species to coexist. Therefore, the high species richness observed demonstrates the ecological importance of this region and thus the necessity of strategies aiming to minimize the impacts caused by trawling fisheries.
Abstract in English:Abstract A series of specimens of Malacoplax californiensis (Lockington, 1877) is reported from the Gulf of California, significantly increasing the known localities for the otherwise rarely reported species from 3 to 12. Depth range is increased to 110‒114 m on the continental shelf. Environmental conditions associated with the crabs were: 12.4‒27.0°C; 1.9‒5.0 ml/l O2; 58‒98% sandy sediments. Males and females were sexually distinct even at small sizes (4.2 mm and 3.5 mm CW, respectively). Two small specimens were infested with a rhizocephalan, a condition not reported previously for this species of panopeid.
Abstract in English:Abstract Body fouling has been reduced by grooming behaviors. In decapods, grooming has been focused on gills, sensory structures, and jointed appendages. In this study, grooming behaviors of the spider crab, Libinia dubia H. Milne-Edwards, 1834, were examined; this brachyuran crab decorates and camouflages body regions by attaching materials onto hooked setae. The relationship between grooming and these camouflaged body regions was unknown. Six observational and experimental studies examined the grooming frequency, duration of grooming behaviors, body regions groomed, variance of these behaviors in the presence of another individual, and the efficiency of these grooming behaviors at removing gill fouling. Sensory and respiratory structures were groomed most frequently and for the longest duration, not body regions with decorations and hooked setae. Crabs in isolation exhibited the highest grooming time budget (5.22%). The presence of another conspecific decreased the grooming time budget (0.67%), and primary actions (e.g., fighting, displaying, mating) became priority. Ablation of a gill-grooming appendage did not impact fouling on gills. Grooming as a secondary action was supported. Reasons for not grooming body regions with hooked setae were discussed. Spider crabs had a lower time budget for grooming compared to most decapods, but similar to another brachyuran.
Abstract in English:ABSTRACT Isopods consume feces in laboratory conditions. We investigated the effects of coprophagy on food consumption and assimilation and on isopod biomass to determine the best methodological design for feeding performance experiments. We used three species of isopods representing different eco-morphological groups and two leaves with different nitrogen content. We tested three treatments: (1) free access to feces; (2) periodic removal of feces and (3) net acting as a barrier to the feces. We did not find significant difference in any isopod or leaf species for consumption rate. Assimilation efficiency did not differ significantly for any isopod or leaf either. Only growth rate was significantly different, but only for the species Atlantoscia floridana (Van Name, 1940) with the leaf Machaerium stipitatum, and it may be due to the short duration of experiments and the isopods’ susceptibility to environmental changes. Thus, we recommend the treatment access to study consumption and growth rates since it does not require any special material or extra time. If the focus is assimilation efficiency, we suggest the treatment removal because it provides more accurate values. Furthermore, more fragile species such as A. floridana require larger sample number and/or longer experiment duration for more reliable data analyses.
Abstract in English:Abstract The moult cycle of crustaceans is continuous and during different stages of this cycle, physiological, biochemical and morphological changes occur. Therefore, understanding the different stages of the moult cycle in the target species becomes critical for a wide range of biological studies. Here we describe the natural cycle changes in the freshwater shrimp Palaemon argentinus and identify two new substages of post-moult, B1 and B2, that are substages occurring before the intermoult, a stage widely used in crustacean studies. Furthermore, we present a more detailed description of stages already known, describing modifications of the structures and its presence or absence in each stage, in conjunction with explanatory pictures. We also indicate the duration for each stage of the cycle, thus expanding our knowledge of the moult cycle and setogenesis for P. argentinus.
Abstract in English:Abstract The Indo-Pacific swimming crab Charybdis hellerii (A. Milne-Edwards, 1867) is native to the Indo-Pacific Ocean, and occurs as an invasive species along the Eastern American coast, where it was probably introduced in ballast water. The present study evaluated the osmoregulation and salinity tolerance of C. hellerii in Paranaguá Bay, Paraná, Brazil, an estuary under the constant threat of introduction of non-native species. The crabs were abruptly submitted to salinities of 10, 20, 30 (control), and 40 PSU for 24h. Hemolymph osmolality showed either an increase or a decrease following the changes in water salinity, presenting a pattern of hyper-osmoconformation. Muscle water content was stable at salinities from 20 to 40 PSU, and increased after exposure to 10 PSU indicating cellular swelling. At 10 PSU a physiological limit was reached, indicated by the failure of the capacity to regulate tissue water content. Although adult C. hellerii tolerate a wide range of salinities for 24 h, its osmoregulatory ability indicates a possible advantage for its establishment in estuarine waters with salinities <20 PSU. The salinity tolerance and osmoregulatory data are important basic information to be used in models to predict and prevent the invasion of the species into new areas of the Neotropics.
Abstract in English:Abstract The rare raninid crab Umalia trirufomaculata (Davie and Short, 1989) is recorded from India for the first time. It is redescribed and compared at length with the related but poorly known U. misakiensis (Sakai, 1937) on the basis of a good series of specimens from the Philippines. Some of the supposed differences which have been documented between the two taxa (e.g., carapace proportions and features of the cheliped) are not valid; while new distinguishing characters associated with the male pleon and gonopods are observed.
Abstract in English:Abstract Mysidopsis gemina n. sp. is described from protected and exposed beach habitats in the provinces of Puntarenas and Guanacaste on the northern Pacific coast of Costa Rica. Morphologically, M. gemina most closely resembles M. furca Bowman, 1957 known from the Atlantic and Gulf Coasts of North America. Both these species are unique within the genus by their distinctively sexually dimorphic telsons. The new Costa Rican species can be distinguished from M. furca and other species of Mysidopsis by a combination of having a male with biarticulated endopods on the first pleopods and pleopods 2-5 with large plate-like pseudopodia (exites). The occurrence of these characters and morphological features within the subfamily Leptomysinae is discussed.
Abstract in English:Abstract Many monitoring studies use marking techniques to obtain dispersal data on individuals. Marking procedures may influence the vital activities of the terrestrial isopods, such as feeding behavior. The objective of this study was to identify the efficiency of different materials for external marking of woodlice and the influence on their feeding performance. Cyanoacrylate glue + glitter and nail polish were used as separate marking materials on three species: Balloniscus glaber, Benthana picta and Armadillidium vulgare. The material efficiency was compared using Kaplan-Meier curves and Log-Rank analysis. Individuals were fed with leaf discs of Machaerium stipitatum for feeding performance trials, and consumption rates were compared using ANOVA (α<0.05). There was no difference in durability between the materials used for external markings, except between marked and unmarked Benthana specimens when the observation period exceeded 15 days (Log-Rank=8.446, p=0.015). Nail polish was considered more suitable for feeding experiments. Statistical differences in consumption rates were observed only between the marked individual treatments of Benthana (ANOVA, F=7.5440, p=0.0002). These results indicate that external marking does not affect the feeding habits of the animals and suggest that this technique can be used to monitor dispersal of terrestrial isopods in field conditions for approximately 15 days.
Abstract in English:Abstract A large number of specimens (2765) of the acorn barnacle Balanus trigonus Darwin, 1854, were observed on the spiny lobster Panulirus gracilis Streets, 1871, in western Mexico, including recently settled cypris (1019 individuals or 37%) and encrusted specimens (1746) of different sizes: <1.99 mm, 88%; 1.99 to 2.82 mm, 8%; >2.82 mm, 4%). Cypris settled predominantly on the carapace (67%), mostly on the gastric area (40%), on the left or right orbital areas (35%), on the head appendages, and on the pereiopods 103. Encrusting individuals were mostly small (84%); medium0sized specimens accounted for 11% and large for 5%. On the cephalothorax, most were observed in branchial (661) and orbital areas (240). Only 40-41 individuals were found on gastric and cardiac areas. Some individuals (246), mostly small (95%), were observed on the dorsal portion of somites. Of the encrusting individuals, 18% were dead with no clear pattern in localization, but less common (7%) on dorsal than on lateral portions (right, 18%; left, 32%). Larger specimens (up to 11 mm) were observed in other lobsters from different catches. Previous presence of Cirripedia in decapod crustaceans, size range in the material examined, settlement patterns, and growth of the barnacles are discussed.
Abstract in English:Abstract The present study provided information extending the known geographical distribution of the calappid crab Cryptosoma balguerii (Desbonne in Desbonne and Schramm, 1867). We provide new data that extends the range of this species in the western Atlantic farther to the south in the Brazilian region, State of São Paulo and check its identification by molecular tools within Cryptosoma and other calappid crabs. New records of marine species provide a baseline for a better understanding of the biodiversity of ecological provinces. This work is an example of the importance of an exhaustive and continuous investigation on the biodiversity of subtidal rocky bottoms.
Abstract in English:Abstract Longevity information was collected from 219 literature sources for 244 decapod crustaceans, representing 1.7% of species, 4.8% of genera and 30% of families. Reliable methods of age determination (laboratory rearing, mark-recapture method, growth models, lipofuscin method) revealed longevities from 0.1 to 72 years, corresponding to a 700-fold difference between the shortest and longest lived species. The mean longevity of the species included in this article is 7.1 years (SD=10.18; CV=142.9%); 61.1% of the species live less than 5 years, 29.5% live between 5 and 20 years, and 9.4% live longer than 20 years. The basal Dendrobranchiata have a mean longevity of only 2.1 years whereas the Achelata have a mean longevity of 27.2 years. The oldest decapod aged with a direct method is a hermit crab that was reared in captivity for more than 42 years. The particularly long-lived species belong to different families of the infraorders Achelata, Astacidea, Anomura and Brachyura. Average longevity is highest in semiterrestrial and terrestrial habitats (13.0 years), followed by freshwater (7.2 years) and marine and brackish waters (6.0 years). The deep sea, polar waters, freshwater caves and terrestrial environments apparently promote the evolution of high life spans.
Abstract in English:Abstract Here, we report the first record of the marine copepod Oithona attenuata Farran, 1913, in Brazil, from a costal station near Cabo Frio Island, Arraial do Cabo Municipality, Rio de Janeiro State. Specimens were found during March and May 2011 in zooplankton samples obtained from horizontal hauls using a plankton-net with a 100μm mesh size, and mouth opening of 40 cm diameter.
Abstract in English:Abstract The family Bopyridae Rafinesque, 1815 is comprised of parasitic isopods with a life cycle involving an intermediate host (copepod) and a definitive host (decapod crustacean). The genus Anuropodione Bourdon, 1967 occurs in all oceans and encompasses five species that are only known as parasites of squat lobsters belonging to the genus Munida Leach, 1820. Despite the broad distribution of the genus, no species has ever been recorded from the South Atlantic. A total of 416 specimens of Munida iris A. Milne-Edwards, 1880 were collected in Potiguar Basin around the isobaths of 400 m, including 24 individuals (5.77%) containing parasites within their branchial chambers. Male parasites showed considerable variability in the number of pleomeres, with many showing four pleomeres, a number previously unknown for males of any species in the genus. These specimens represent the first occurrence of the genus Anuropodione and the species A. carolinensisMarkham, 1974 from the South Atlantic (Brazilian waters).
Abstract in English:Abstract Kerala has the highest known diversity of freshwater crabs among the Indian states, and many more species are likely to be added to the state, especially from the Western Ghats. The present specimens from the Western Ghats of Kerala add two more species records to Kerala: Oziotelphusa wagrakarowensis (Rathbun, 1904) and Vanni nilgiriensis (Roux, 1931). Although O. wagrakarowensis was reported from the Indian states of Andhra Pradesh, Karnataka, and Maharashtra, it has not been recorded from Kerala previously. The present record of O. wagrakarowensis also constitutes the first reliable report of the species from the Western Ghats. The other species, V. nilgiriensis, was previously known from the Western Ghats of Karnataka and Tamil Nadu. Kerala now includes 37 species of gecarcinucid crabs with the addition of these two new records whereas the Western Ghats of India currently has 59 species.
Abstract in English:ABSTRACT The mangrove crab, Parasesarma bengalense (Davie, 2003), was previously reported in an ecological study from the Coringa Wildlife Sanctuary of Andhra Pradesh on the east coast of India. No specimen, however, is readily available to confirm the identity of P. bengalense from the Coringa Wildlife Sanctuary. The present study confirms the presence of P. bengalense in Indian waters for the first time based on the collections from Kerala and Maharashtra in the west coast of India (Arabian Sea). The distributional range of P. bengalense is now extended to the Arabian Sea because the species was previously known only from the Bay of Bengal and the Andaman Sea. India now has 918 species of marine brachyuran crabs and six species of Parasesarma De Man, 1895, including the present new record. The west coast of India is home to 465 brachyuran species whereas Kerala and Maharashtra coasts now contain 180 and 131 marine crab species, respectively. Parasesarma bengalense can be distinguished among the Indian species of Parasesarma except for P. bidens (De Haan, 1835) mainly by the presence of a prominent epibranchial tooth with a distinct notch. Parasesarma bengalense is distinct from P. bidens mainly by its male cheliped, which has a greater number of dactylar tubercles and a lesser number of teeth on the transverse crests of the palm.
Abstract in English:Abstract The pelagic shrimp Petalidium suspiriosum described from off Clarion Island, Mexico, in the eastern Pacific, is recorded for the first time in the Gulf of California. The unique male specimen was captured in deep water of the central Gulf of California. Diagnostic characters, including the petasma, are illustrated and briefly described.
Abstract in English:Abstract The present paper reports the occurrence of the rare parthenopid species Rhinolambrus lippus (Lanchester, 1901) for the first time from India. The species is so far reported from Malaysia, Djibouti and Madagascar.