Brachyuran Decapods Research Articles

Oligocene crabs (Decapoda: Brachyura) from the Asmari Formation in Yasuj area (SW Iran)

New findings of crustacean decapod brachyurans from the Rupelian period (lower Oligocene) in Iran are presented in this study. In particular, Lophoranina sp. and Palaeocarpilius cf. P. rugifer Stoliczka, 1871, from the Rupelian strata were found in two previously unexplored localities, Abshar and Vezg near Yasuj in the southwestern region of Iran. The discovery contributes to fill the gap in the record of brachyuran decapod crustaceans in Iran during the Eocene and Miocene periods. The presence of both genera in the Oligocene of Iran suggests a certain degree of faunal similarity among brachyurans on both sides of the Tethys Realm.

First in situ observations of the benthic-demersal fauna on the upper continental slope off Punta Pichalo (19°36'S), northern Chile

An autonomous lander equipped with a video camera (dropcam) was used for in situ observations of the bento-demersal macrofauna on the upper continental slope off Punta Pichalo in northern Chile, an area of permanent coastal upwelling processes, located ~70 km north of Iquique. The lander was deployed at nine stations and between 227 and 798 m of depth. According to morphological characteristics, 34 operational taxonomic units (OTUs) were identified to the lowest taxonomic level; 24 belonged to macroinvertebrates and 10 to fishes. Macroinvertebrates comprised 9 OTUs of crustaceans, seven cnidarians, and six echinoderms. Fishes included 3 OTUs of the order Chondrichthyes, 3 belonging to macrourid. Perciformes, Anguilliformes, and Alepocephaliformes were represented by one OTU each. Also, we observed one species of lanternfish (Myctophidae). Apart from the brachyuran decapod Lophorochinia parabranchia Garth, 1969 and euphausiids, all species were observed at depths greater than 560 m. The presence of one individual identified as the granulate dogfish Centroscyllium granulatum Günther, 1887 extended the known distribution range of this species about 1000 km to the north. Images taken at 795 m showed Bathyraja peruana McEachran & Miyake, 1984. Our study suggests that the upper continental slope of northern Chile harbors nearly undiscovered biodiversity, worth to be studied more intensively to complete the comparable sparse knowledge about marine biodiversity and species distribution at the continental margin in front of Chile.

Jurassic brachyurans of the genus Bucculentum.

The genus Bucculentum Schweitzer Feldmann, 2009 is exceptional among the brachyuran decapods in having the augenrest dorsally inclined. Hitherto, the genus comprised two species, both from European Upper Jurassic localities; here, further two species are described, Bucculentum horstkuscheli, n. sp. and B. plettenbergense, n. sp., which differ in their proportions of the carapace regions and especially in their shapes of the augenrest. A newly described feature shared by all congeneric species is the groove extending from the centre of the dorsal portion of the augenrest and terminating towards the cervical groove. The function of this groove could have been to lead the water stream out from the augenrest to cleanse impurities from the muddy sea bottom, where these crabs are supposed to have lived.

First report of decapod crustaceans from the middle–late Miocene of Valmarecchia, Romagna Apennines (Emilia-Romagna, Italy)

Axiidean and brachyuran decapods are reported from the middle–late Miocene pre-evaporitic deposits of several localities along the Valmarecchia (Rimini) in the Romagna Apennines (Emilia-Romagna). Goneplax rhomboides (Linnaeus, 1758), already known from the Miocene of Italy, has not been recorded previously in this area, while the record of Chlinocephalus demissifronsRistori, 1886 expands the stratigraphic range of the genus, previously known only from the Pliocene and Pleistocene of Italy. Moreover, some specimens are assigned in open nomenclature to LobocarcinusReuss, 1857, already known from the Miocene of Italy. Finally, some loose chelae are assigned to the families Callianassidae and Eucalliacidae, respectively, without generic and specific assignment. The Valmarecchia decapod assemblage enlarges the knowledge on the composition and distribution of the decapod fauna along the palaeo-Adriatic Gulf before the Messinian Salinity Crisis of the Mediterranean Basin.

Restructuring of the \u2018Macaronesia\u2019 biogeographic unit: A marine multi-taxon biogeographical approach

The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term “Macaronesia”. This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islands.

Decapod assemblage from the late Miocene (early-middle Messinian) of the Romagna Apennines nearby Brisighella, Emilia-Romagna (N Italy)

An assemblage of axiidean and brachyuran decapods is reported from the late Miocene pre-evaporitic (early-middle Messinian) limestone of Cò di Sasso, nearby Brisighella (Ravenna, Emilia- Romagna), located in Romagna Apennines (NE Italy). Except Monodaeus bortolottii Delle Cave, 1988 (Xanthidae MacLeay, 1838), which is reported here for the first time in Miocene, all the other specimens have been assigned to species previously known in the Italian Miocene (Messinian s.l.), but never reported in this area. The report of Galathea cf. G. weinfurteri Bachmayer, 1950 (Galatheidae Samouelle, 1819) and Medorippe ampla Garassino, De Angeli, Gallo and Pasini, 2004 (Dorippidae MacLeay, 1838) enlarges the stratigraphic range of these Miocene species. This report enlarges our limited knowledge on the composition and distribution of the axiidean, anomuran, and brachyuran decapods during the early-middle Messinian before the evaporitic event in the Mediterranean Basin.

Decapod crustaceans from the late Pliocene (Piacenzian) nearby Faenza (Emilia-Romagna, N Italy)

Several specimens of anomuran and brachyuran decapods are reported from the late Pliocene clays (Argille Azzurre Fm.) at localities nearby Faenza (Ravenna, Emilia-Romagna), located in the foothills of Romagna Apennines (NE Italy). The specimens were assigned to species already reported from the Pliocene of Italy, but never previously recorded in this area. This new report enlarges our knowledge on the composition and distribution of the brachyuran decapods along the Pliocene coastline of the Adriatic Gulf of the paleo- Mediterranean Sea.

First record of three brachyuran decapods (Inachidae, Polybiidae, Thiidae) from the Canary Islands (NE Atlantic)

In the present account three brachyuran decapods,Macropodia linaresiForest & Zariquiey Álvarez, 1964 (Inachidae),Liocarcinus navigator(Herbst, 1794) (Polybiidae) andThia scutellata(Fabricius, 1793) (Thiidae), are recorded for the first time from the Canary Islands. This is the southernmost record ofM. linaresi. Crabs were caught in the frame of a dredging survey. Characteristics of the dredge stations are given, including the identification of 11 accompanying decapod species and 6 marine algae and plants characterizing their habitats.

Larval morphology of the family Parthenopidae, with the description of the megalopa stage of Derilambrus angulifrons (Latreille, 1825) (Decapoda: Brachyura), identified by DNA barcode

Although Parthenopidae is a brachyuran decapod family comprising almost 140 species, there is little knowledge about its larval morphology. There are only two complete larval developments reared in the laboratory and some larval stages described for seven species. In the present work these data are compared and analysed. A summary is made of the larval features that characterize parthenopids that can be used to distinguish them from other brachyuran larvae. In addition, the megalopa stage of Derilambrus angulifrons and Parthenopoides massena was collected from plankton and identified by DNA barcodes. The morphology of the megalopa of D. angulifrons is described for the first time, and that of P. massena is compared with a previous description.

Is larval dispersal a necessity for decapod crabs from the Amazon mangroves? Response of Uca rapax zoeae to different salinities and comparison with sympatric species

Salinity may play an important role in the larval Biology and Ecology of many brachyuran decapod crustaceans. Usually, ontogenetic changes in salinity tolerance represent a good indicator of larval dispersal in marine coastal ecosystems. In an experimental laboratory study, we investigated the effects of eight different salinities (Sal. 0–35) on zoeal development of the neotropical fiddler crab Uca rapax from a northern Brazilian estuary. In the study area the species reproduces year-round, including the wet season when low salinities (≤5) are frequent, resulting from heavy tropical rainfalls and input of freshwater mostly from the Amazon River. Larval survival and development duration from hatching to megalopa of U. rapax were significantly affected by salinity. All larvae died in Sal. 0–20, while they successfully developed through five zoeal stages to megalopa in higher salinities (Sal. 25–35). However, in Sal. 25 the survival rate was still significantly lower (33.8±4.8%) and the zoeal development duration was longer (13.7±0.5days) than in salinities 30 and 35, where >90% of the larvae successfully survived after an average of 11.8–12.4days of development, respectively. Our results strongly suggest that the early life-history stages of U. rapax perform ontogenetic migrations towards adjacent coastal or fully marine waters to develop in favourable high salinities. Comparison with two other sympatric crab species, e.g. Ucides cordatus and Uca vocator, suggests that the larval ‘export’ strategy is a convergent adaptation exhibited by decapod species in the Amazon region to avoid mass mortality within parental mangroves that are frequently subjected to strong salinity fluctuations caused by the specific meteorological and hydrological conditions.

Invasion of the Atlantic rock crab (Cancer irroratus) at high latitudes

With the increase in global oceanic trade the establishment of non-indigenous marine organisms has become a major environmental and economic problem worldwide. Recently, the Atlantic rock crab (Cancer irroratus) was reported in Icelandic waters, Eastern North Atlantic. This is the first record of this relatively large crab species outside its natural range, i.e. the east coast of North America. The crab was most likely transferred to Iceland as larvae in ballast water and has successfully established a reproducing population in Icelandic waters. The species is distributed along the southwestern- and western-coast of Iceland. Adult specimens are now common in Faxafloi Bay, Southwest Iceland, but with sporadic occurrences in western and northwestern Icelandic waters. The green crab (Carcinus maenas) and the spider crab (Hyas araneus) are the only native brachyuran decapod species commonly found in its new habitat, but despite its recent colonization the rock crab was the most abundant brachyuran in the areas studied in southwest Iceland. Egg bearing rock crab and green crab females were found from June to October, while egg bearing spider crab females were seen from July to December. In Southwest Iceland both rock crab and green crab larvae were abundant in mid-summer but rare in both spring and autumn, which is opposite of what was observed for the spider crab. The size and abundance of adult crabs, their reproductive conditions, and occurrence of all larval stages, indicate that the Atlantic rock crab has successfully colonized Iceland.

No evidence of host specialization in a parasitic pea-crab exploiting two echinoid hosts

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 475:167-176 (2013) - DOI: https://doi.org/10.3354/meps10131 No evidence of host specialization in a parasitic pea-crab exploiting two echinoid hosts Q. Jossart1, 2,*, B. David2, C. De Bruyn1, 2, C. De Ridder1, T. Rigaud2, R. A. Wattier2 1Laboratoire de Biologie Marine (CP 160/15), Université Libre de Bruxelles (ULB), 50 avenue F. Roosevelt, 1050 Brussels, Belgium 2Biogéosciences, UMR CNRS 6282, Université de Bourgogne, 6 boulevard Gabriel, 21000 Dijon, France *Email: qjossart@ulb.ac.be ABSTRACT: The pinnotherid crab Dissodactylus primitivus lives parasitically on 2 burrowing echinoid species, Meoma ventricosa and Plagiobrissus grandis. The fecundity of female crabs varies between hosts, and is higher when parasitizing P. grandis than M. ventricosa. Moreover, the hosts present great variations in morphology (size and density of spines). These characteristics suggest the potential to differentiate crabs according to host species. We investigated the genetic (microsatellites) and morphometric (outline analysis) differentiation of this parasitic crab between 2 host species at 1 Jamaican site (Western Lagoon, Discovery Bay), and compared it with geographic differentiation among 4 sites along the north coast of Jamaica. Greater genetic differences between parasites of the 2 sympatric hosts than between parasites of a single host at different geographic locations would indicate host differentiation. Genetic analyses (microsatellites) did not detect spatial differentiation (probably due to local hydrography) or differentiation according to host species. This lack of host differentiation could be explained by mobility of adult crabs between hosts. However, there was weak but significant morphological differentiation between female crabs from the 2 hosts. This morphological difference may reflect constraints due to host morphology. KEY WORDS: Host specialization · Spatial scale · Ectoparasite · Population genetic structure · Microsatellite · Morphometry · Brachyuran decapods · Echinoid Full text in pdf format PreviousNextCite this article as: Jossart Q, David B, De Bruyn C, De Ridder C, Rigaud T, Wattier RA (2013) No evidence of host specialization in a parasitic pea-crab exploiting two echinoid hosts. Mar Ecol Prog Ser 475:167-176. https://doi.org/10.3354/meps10131 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 475. Online publication date: February 14, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Carry-over effects of delayed larval metamorphosis on early juvenile performance in the mangrove crab Ucides cordatus (Ucididae)

Competent larvae of most benthic marine invertebrates including brachyuran decapod crustaceans can delay their settlement and metamorphosis in the absence of suitable environmental cues. This however may carry significant costs for the post-larval performance and fitness of early benthic juveniles. In this paper, we examined in the laboratory whether delayed larval metamorphosis affects early juvenile performance of the mangrove crab Ucides cordatus, measured as survival and growth through the first five juvenile crab stages (JI–JV). We further investigated whether ‘carry-over’ effects of an extended larval period vary intraspecifically among juveniles from three different hatches (F1–F3). Ucides megalopae were cultivated in two treatments. In the first one, the control, megalopae were cultivated continuously in exposure to conspecific crab odours (adult-conditioned seawater=ACSW) until moulting to the first juvenile crab stage. In the second, the delay-treatment, settlement-competent megalopae were kept for 20days in pure filtered seawater without metamorphosis-triggering odours. From day 21 onwards, megalopae were transferred to ACSW to induce larval moult. The results showed that delayed metamorphosis affects early juvenile survival and growth of U. cordatus. In the delay-treatment, survival rates of juveniles (JI–JV) from F1–F3 were 11–31% lower and intermoult development periods 1.5–4.2days longer than in the control. Delayed juveniles (F1–F3) exhibited 9.2–14.1% smaller body sizes (carapace width) and 1.4–3.9% lower growth rates mostly in the first two moulting events compared to specimens derived from non-delayed megalopae. Most of the detrimental effects were observed in almost all five crab stages studied, indicating that the costs of delayed metamorphosis may persist throughout early juvenile development. Juvenile morphology, however, was not affected. Our study also showed that carry-over effects of delayed larval moult vary intraspecifically among offspring produced by different females. This plasticity in phenotypic effects could relate to differences in the nutritional state, health or age of the females, to stressful environments during embryogenesis or to genetic differences. The observed carry-over effects of delayed settlement on early juvenile performance may affect the overall recruitment success and population dynamics of U. cordatus. In the field, such a situation would appear when new mangrove areas void of conspecific crabs are colonized or when degraded sites are re-populated by larvae originating from elsewhere populations.

Spatial variability in the structure of intertidal crab and gastropod assemblages within the Seychelles Archipelago (Indian Ocean)

Tropical nearshore ecosystems represent global hotspots of marine biodiversity and endemism but are often poorly understood and impacted by human activities. The Seychelles Archipelago (Western Indian Ocean) sustains a wealth of marine life, much of which is threatened by rapid development associated with tourism and climate change. Six marine parks exist within the Archipelago, but their biodiversity value and ecological health are poorly known, especially with regards to non-fish and coral species. Here we investigate spatial patterns of littoral biodiversity on 6 islands, 5 of which were granitic and within marine parks, including the first surveys of Curieuse and Ile Cocos. Our surveys formed a nested sampling design, to facilitate an examination of variability in species richness, faunal abundance, taxonomic distinctness and assemblage composition at multiple spatial scales, from islands (>100skm) to quadrats (metres). We identified (mostly to species) and enumerated two target taxa, brachyuran decapod crustaceans and gastropod molluscs, and recorded over 8300 individuals belonging to over 150 species. Crabs and gastropods exhibited different patterns of spatial variability, as crab assemblages were generally more distinct between islands, while gastropod assemblages were markedly variable at the smallest spatial scales of ‘patch’ and ‘quadrat’. Intertidal biodiversity was greatest on Curieuse Island and least at Desroches, the latter was being the only coral atoll we surveyed and thereby differing in its geological and ecological context. We discuss likely drivers of these biodiversity patterns and highlight urgently-needed research directions. Our assessment of the status of poorly-known invertebrate assemblages across the Seychelles will complement more extensive surveys of coral and fish assemblages and, in doing so, provide a useful baseline for monitoring the effects of key stressors in the region, such as coastal development and climate change.

Phylogenetic Analysis and Revised Classification of Podotrematous Brachyura (Decapoda) Including Extinct and Extant Families

Abstract A phylogenetic analysis based upon 30 extinct and extant taxa of podotrematous brachyuran decapods using 74 characters shows that Podotremata sensu Guinot, 1977 is not monophyletic and results in a new classification for these crabs. Four new taxa are recognized at the section-level (Homoloida, Torynommoida, Etyoida, and Dakoticancroida) as well as two new families (Basinotopidae and Xandarocarcinidae). Dromiacea as historically defined is redefined herein to exclude Homoloidea. New generic names Noetlingocarcinus and Xandarocarcinus, and Seorsus millerae new combination also resulted from the work.

Brachyuran decapods (including five new species and one new genus) from Jurassic (Oxfordian-Kimmeridgian) coral reef limestones from Dobrogea, Romania

Brachyuran decapods (including five new species and one new genus) from Jurassic (Oxfordian-Kimmeridgian) coral reef limestones from Dobrogea, Romania

Cenozoic Crustaceans of the East and West Indies

This is an issue of Scripta Geologica from the Nationaal Naturhistorisch Museum, Leiden around a single theme concerning Cenozoic crustaceans edited by Stephen Donovan. The lead-off paper by Schweitzer, Feldmann, and Bonadio (2009) erects a new family of heterotreme Brachyura, Martinocarcinidae, for that old problematic species Martinocarcinus ikeae Bohm, 1922 from the Late Eocene of Java. The authors do a reasonable job of redescribing the species, comparing it to contemporaneous and modern families, and concluding the uniqueness of this form is yet another example of the blast of experimental morphologies at a time in the Eocene of maximal diversity in the Brachyura. This paper highlights anew the fact that understanding family level diversity (Ng et al., 2008) is rather incomplete without inclusion of fossil forms. Collins, Mitchell, and Donovan (2009) have a short paper describing a new species of Pleistocene grapsid from Jamaica, Sesarma primigenium. The material consists of assorted claw parts, and demonstrates the limits of what can be done with these kinds of fossils. Collins, Donovan, and Stemann (2009) review the crustacean fauna from a new Late Pleistocene locality in the Port Morant Formation. The bulk of the fauna consists of claws of thalassinidean and brachyuran decapods. A few barnacles are included. Not much is done with the material except to list and illustrate the species. The final paper by Collins, Portell, and Donovan (2009) presents a more synthetic treatment of Neogene decapods of the Caribbean. The authors offer a useful country-bycountry catalog of what is currently known, but this section is loaded with statements such as this one from page 75 concerning Venezuela: ‘‘Falconoplax kugleri Van Straelen, 1933, has characters in common with Falconoplax bicarinella Collins & Morris, 1976, an Eocene species from Barbados ... .’’ One is left wondering what are those characters, and why is it important to know this: is a phylogenetic connection hinted at, or a possible synonymy? It is all the more intriguing because the discussion lays out in tabular form a great deal of the catalog, except only a single Falconoplax is recorded from the Castilla Formation, Lower Miocene (the F. kugleri I suppose). This was a bit disconcerting until one realizes the F. bicarinella mentioned above is Eocene, and only Neogene material is the subject of the paper. We are getting only half of the picture. An Appendix by Collins formally describes several new taxa. There is a lot of information in this paper, and someday someone will make an interesting story of the evolution of Cenozoic crustaceans of the Caribbean, but that is only hinted at here, e.g., the similarity indexes of Table 5. I wish the authors had gone further. For those interested in the taxonomy and evolution of Cenozoic crustaceans, it will be useful to know this little packet of papers exists.

3-Decanol in the haemolymph of the hermit crab Clibanarius vittatus signals shell availability to conspecifics

Hermit crabs with poor fitting shells are chemically attracted to dying gastropods and conspecifics where a shell may become available. For land hermit crabs, the shell cue is a volatile compound found in the haemolymph. Based on this knowledge, we tested the hypothesis that shell investigation behavior in aquatic hermit crabs, the ancestral predecessors of terrestrial hermit crabs, is also triggered by volatile cues. Volatile compounds from haemolymph of Clibanarius vittatus and Pagurus pollicaris and brachyuran decapod crustaceans were purged from a water–haemolymph solution, trapped in seawater and tested for induction of shell investigation behavior with juvenile C. vittatus. Only volatiles from C. vittatus haemolymph stimulated shell investigation. Volatile compounds were isolated from haemolymph by headspace solid-phase microextraction (SPME) and analyzed by coupled gas chromatography–mass spectrometry (GC–MS). Two prominent compounds were identified, 3-decanol, which was unique to C. vittatus haemolymph, and 2-ethyl-1-hexanol, which was present in the haemolymph of all 4 crustacean species. In shell investigation bioassays, 3-decanol from C. vittatus haemolymph stimulated shell investigation behavior, while 2-ethyl-1-hexanol did not. In bioassays with synthetic 1-, 2-, 4-, and 5-decanol, shell investigation behavior was evoked by 1-decanol, 5-decanol and 3-undecanol. There was no response to 2- and 4-decanol. The response of C. vittatus to volatile shell cues supports the hypothesis that volatile cue detection evolved prior to the occupation of terrestrial niches by crustaceans.

Studies on the short-term fffects of the mobil Idoho oil Spill on the Littoral Biota of Southeastern Nigeria

Quantitative surveys of the intertidal macro-fauna were conducted during September-October 1998 along transects established at various locations along the Nigeria coastline, following the rupture of a 24-inch pipeline at Idoho, off the Gulf of Guinea, southeastern Nigeria on 12 January 1998. Samples were taken within impacted areas and at control unpolluted sites approximately 5 km to the east of the Idoho off-shore platform. Spilled oil moved rapidly ashore and into river mouths, and estuaries and their mangals shortly after the spills. Biomass of macrofauna in the impacted areas tended to decrease with level of oiling, as the mean abundance decreased rapidly to about 50% of that found on the control unpolluted sites. Edible gastropod, mainly species of Tympanotomus fuscatus, and the brachyuran decapod, Ucatangeri, typically consumed by coastal inhabitants, had reduction in mean densities (up to 62%) in the oiled Bonny, Brass, Lagos and Forcados than in the non-oiled areas of Imo, Andoni and Cross River, showing partial recovery of the environment from the debacle after 9 months. The ecological implications of these findings are discussed.

Reproductive aspects of two bythograeid crab species from hydrothermal vents in the Pacific-Antarctic Ridge

Bythograea laubieri, B. vrijenhoeki and alvinellid polychaetes dominate the vent fauna of the Pacific-Antarctic Ridge. We studied gonadal development in females of both crabs. They have ovary microstructures characteristic of brachyuran decapods. The ovaries are paired organs overly- ing the hepatopancreas beneath the carapace. Oogonia proliferate from the germinal epithelium and develop into previtellogenic oocytes that grow to 60 Mm before undergoing vitellogenesis. The observed maximum sizes of mature oocytes were 209 Mm in B. laubieri and 138 Mm in B. vrijenhoeki. No ovigerous females were found in the samples, which agrees with the segregation behaviour of ovigerous females away from the direct influence of the active chimney in some related species. In contrast to other species of bythograeid crabs, the oocyte size-frequency data suggest that B. laubieri and B. vrijenhoeki lack synchrony in reproduction of the population as a whole. Synchrony and sea- sonality in reproduction of B. thermydron have been linked to the formation of phytoplankton blooms in surface waters. We suggest that the biogeography of bythograeid crabs is determined by contrast- ing oceanographic regimes that influence the reproductive patterns observed in different species.