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A new species of yeti crab is described from a hydrothermal vent field near the equatorial Eastern Pacific Rise (EPR)-Galapagos Microplate at a depth of 1,628 m. Kiwa gemma n. sp. is the fifth species of the family Kiwaidae Macpherson, Jones & Segonzac, 2005 to be described thus far. The new species can be distinguished from other congeners by having the lateral margin of chelipeds without spines, slender and mostly straight chelar fingers, and the spinose mesial margin of the endopod of the uropod. Also notable are the unique short, stiff, scaly-tipped setae on the antennal peduncles and chelipeds, which have not been reported to occur in congeners. A key to the species of the genus Kiwa Macpherson, Jones & Segonzac, 2005 is provided. [ABSTRACT FROM AUTHOR]

Seven species of chirostyloid and galatheoid crustaceans, including three new species, are reported from the eastern Arabian Sea and Bay of Bengal, India, based on material from depths ranging from 32–1420 metres. Trapezionida samudrika sp. nov. appears close to T. munin (Komai, 2011), but is distinguished by the shape of the carapace and fourth thoracic sternite, the armature of the third maxilliped merus, the length and armature of the cheliped, and the armature of the ambulatory legs. Paramunida travancorica sp. nov. differs from its closest species P. bineeshi Macpherson, Chan, Kumar & Rodriguez-Flores, 2020, P. mozambica Cabezas, Macpherson & Machordom, 2010, and P. stichas Macpherson, 1993 in the morphology of the carapace and antennular and antennal peduncles. Munidopsis bhavasagara sp. nov. is similar to M. dentifalx Osawa, Lin & Chan, 2007, but distinguishable by the absence of a pair of elevated, short ridges on the epigastric carapace region and the proportionally shorter chelipeds and ambulatory legs. The present material of Munidopsis unguifera Alcock & Anderson, 1894 represents only the third record of the species in India and a detailed description and illustrations are provided to supplement the previous descriptions. The remaining three species, Eumunida multispina Komai, Chakraborty, Paramasivam & Gidda, 2019, Munidopsis scobina Alcock, 1894, and M. stylirostris Wood-Mason in Wood-Mason & Alcock, 1891, are recorded from additional localities within their known geographic regions. [ABSTRACT FROM AUTHOR]

Squat lobsters constitute an exceptional group to address evolutionary studies in marine species because of their high diversity at multiple taxonomic levels. The families included within Galatheoidea are characterized by morphological, molecular, and ecological differences. Previous phylogenetic reconstructions have considered either Galatheidae, Porcellanidae, or even Munidopsidae as the most derived family within Galatheoidea, but evolutionary relationships within the superfamily have not been fully resolved yet. In order to test previous phylogenetic hypotheses on the relative placement of Porcellanidae within the Galatheoidea, and further characterize mitochondrial gene order in Munidopsidae, the first complete mitochondrial genomic sequence of a Galatheidae squat lobster (Galathea aegyptiaca) and the partial mitogenome of Munidopsis polymorpha are reported here. These new sequences complement previous studies to include all extant families and provide further evidence on the importance of mitochondrial gene rearrangements in Galatheoidea. Implications of the new phylogenetic data on the evolution of carcinization within Anomura are also discussed. [ABSTRACT FROM AUTHOR]

The genus Coralliogalathea of the family Galatheidae is easily differentiated from other genera in the family by its small size, the presence of three to four small lateral teeth on the rostrum and the lack of the first pair of gonopods in males. The genus currently consists of only a single species, Coralliogalathea humilis, which lives in close association with corals in the Indian and Pacific Oceans. Using material collected across its distribution, we analysed both morphological characters and molecular markers (COI, 16S, 28S and 18S) to investigate cryptic species diversity, phylogenetic relationships within the genus, and the phylogenetic position of Coralliogalathea within the family Galatheidae. Our results support the validity of the two species previously synonymized with C. humilis and three new sympatric species found in Espiritu Santo, Vanuatu. Although these species are distinguishable only by subtle morphological characters, they are highly dissimilar genetically and constitute relatively deep divergent lineages. Furthermore, phylogenetic analyses of Galatheoidea resolved Coralliogalathea as an ancient genus within the superfamily that most probably diversified during the Eocene. [ABSTRACT FROM AUTHOR]

The growth and reproduction investment of the young of the year (0+) of the squat lobster Munida gregaria in San Jorge Gulf, Argentina, were analysed. Moult cycle and size frequency distribution were studied in monthly field samples. Experiments to determine moult increments and intermoult duration were conducted. Sexual maturity, fecundity and reproductive output were analysed in field samples. In addition, maturity experiments in laboratory cultures were conducted. After settlement (November), juveniles showed fast growth until winter (July) and growth restarted in September-October. At the beginning of the mating period (early June), males 0+ exhibited mature gonads, whereas females 0+ only showed previtellogenic oocytes. Experimental data showed that females with developed gonads had smaller-size increments in the previous moult. Fecundity and reproductive output were significantly lower in females 0+ than in older females. The early life history of M. gregaria in San Jorge Gulf differs from that of southern populations as those of Beagle Channel and Strait of Magellan due to faster growth and early reproductive investment. Our results suggest that females 0+ of M. gregaria have two investment strategies: early maturity with low fecundity and delayed maturity with higher future fecundity.

Eumunida picta Smith, 1883, was considered for over a century an amphi-Atlantic species and the only representative of the genus in the Atlantic Ocean, until being split into three species: E. picta sensu stricto (from the northwestern Atlantic), E. bella de Saint Laurent & Macpherson, 1990 and E. squamifera de Saint Laurent & Macpherson, 1990 (from the northeastern and southeastern Atlantic, respectively). Eumunida is now expanded to include a new species, E. notialis, from off the Brazilian coast. Hence, this is the first record of Eumunida and Eumunididae from the southwestern Atlantic. The new species differs from all its Atlantic counterparts in having (1) four hepatic spines; (2) two carapace inframarginal spines; (3) the distal end of the antennal acicle nearly reaching to the articulation between fourth and fifth antennal segments; and (4) the anterolateral spine of the second pleonal tergite obsolete. [ABSTRACT FROM AUTHOR]

Como aporte a la dinámica poblacional de especies que constituyen recursos pesqueros, se analizaron 160 muestras de zooplancton obtenidas con redes Bongo en 40 estaciones oceanógraficas entre Caldera y Coquimbo, en octubre y diciembre de 2005. De ellas se separó la totalidad de las larvas de crustáceos decápodos y se identificaron las de Heterocarpus reedi, Cervimunida johni y Pleuroncodes monodon. Las mayores abundancias de zoeas tempranas de las tres especies se encontraron en octubre en la zona de Coquimbo, mientras que en diciembre predominaron los estados más avanzados de desarrollo. En la zona de Caldera, en ambos meses de muestreo, predominaron los estados avanzados de desarrollo de H. reedi y P. monodon y zoeas tempranas de C. johni. La frecuencia de ocurrencia de las larvas de H reedi en la zona de Coquimbo fue similar en ambos meses, mientras que en la zona de Caldera fue mayor en octubre. La frecuencia de ocurrencia de las larvas de P. monodon y C. johni fue mayor en octubre en ambas zonas. Todas las megalopas capturadas en las dos zonas y meses de muestreo corresponden sólo a un morfotipo, con características morfológicas similares a los juveniles más pequeños de P. monodon. Sobre la base de la distribución y abundancia de larvas de las tres especies, se postula que el desove ocurre antes en la zona de Caldera que en la de Coquimbo, principalmente en zonas próximas a la costa, dada las diferencias de abundancia de los estados de desarrollo.To better understand the population dynamics of fishery resource species, 160 zooplankton samples were obtained with a Bongo net at 40 oceanographic stations around Caldera and Coquimbo in October and December, 2005, and analyzed. All crustacean decapod larvae were sorted, and Heterocarpus reedi, Cervimunida johni, and Pleuroncodes monodon larvae were identified. For all three species, the highest abundances of early zoea were found in October in Coquimbo, whereas advanced larval stages were predominant in December. In Caldera, advanced larval stages of H. reedi and P. monodon, and early zoeas of C johni were dominant during both sampling months. The frequency of occurrence of H. reedi larvae was similar during both sampling months in Coquimbo and greater in October in Caldera. The frequency of occurrence of the larvae of P. monodon and C johni was greater in both areas in October. All the megalops captured in both zones and sampling months corresponded to a single morphotype, with morphological characteristics similar to the smallest P. monodon juvenile specimens. Based on the larval distribution and abundance of these three species, it is postulated that spawning occurs earlier in the Caldera área than around Coquimbo, mainly in areas near the coast, given the differences in abundance of the developmental stages.

Squat lobsters are highly diversified and widespread decapods, of which only three species form pelagic swarms. Here we infer the expansion of Munida gregaria populations in the Beagle Channel and the Argentine Patagonian Shelf by means of acoustic surveys of pelagic swarms. We also describe the habitat characteristics in which these swarms occur. Acoustic data was collected during three multidisciplinary scientific cruises on board of the R/V Puerto Deseado during 2009, 2012 and 2014. Despite differences in the environmental conditions between the two surveyed areas, between 2009 and 2014 pelagic swarms increased their occurrence and abundance both in the Beagle Channel and on the Argentine Patagonian Shelf. Towards the end of the studied period, pelagic swarms of M. gregaria occurred in new locations, supporting the notion of a population expansion. Within the Beagle Channel swarm expansions were more marked than on the Patagonian Shelf. We here postulate that M. gregaria expansions occur in association with productive areas of the Argentine continental shelf, such as frontal zones, favoured by the squat lobster phenotypic plasticity that permit to exploit resources in both the neritic and benthic environments. At a regional scale on the Patagonian Shelf, three main groups of pelagic swarms of M. gregaria were clearly associated to respective frontal zones. The information presented here is necessary to understand fluctuations in both distribution and abundance patterns of a key species on the Argentine continental shelf. These fluctuations could be direct or indirect indicators of changes in the ecosystem. [ABSTRACT FROM AUTHOR]

The article presents a study about the frequency of occurrence (FO) and the abundance of squat lobster or Munida gregaria in the fisheries in San Jorge Gulf, Argentina. It examines the impact of low selectivity and high incidental catch of squat lobster in the marine communities. It also cites the effect of fisheries in the ecosystem along with the use of unutilized species in fishing.

The 'East Pacific Barrier' has been recognized as the World's largest marine biogeographic barrier. Munida gregaria is the only species of its family with transpacific populations; however, it still remains to be elucidated whether these two distantly located populations belong to the same species. In this study, we investigated the genetic cohesion of M. gregaria across the East Pacific Barrier by analyzing mitochondrial markers. Cytochrome oxidase subunit I and NADH dehydrogenase subunit 1 genes were sequenced for individuals from different areas, i.e., the southeast Pacific, the southern tip of South America, the southwest Atlantic, and the southwest Pacific. A median-joining network, pairwise Fs, genetic diversity statistics, and neutrality tests were computed. Our results, i.e., the absence of different haplogroups on both sides of the East Pacific Barrier and existence of shared haplotypes, showed that populations on both sides of this barrier belong to the same species. At a population genetic level, our results suggest that individuals from both regions have been connected, since although some differentiation was found between the southern tip of South America and the southwest Pacific, the southeast Pacific and southwest Atlantic showed no signs of differentiation from the southwest Pacific. In addition, our results provided evidence of a population expansion in southern South America during the Pleistocene. The role of Pleistocene glaciations and the Antarctic Circumpolar Current in shaping the distribution of sub-Antarctic marine invertebrates is discussed. [ABSTRACT FROM AUTHOR]

Distribution of squat lobsters of the genera Gastropthychus (one species), Uroptychus (1), Janetogalathea (1), Galacantha (1), Munidopsis (8), and Munida (7) in the Gulf of California, Mexico, was plotted vs. the localization of the Oxygen Minimum Zone (OMZ) using bottom projections of the 0.50, 0.25, 0.10, and 0.05 ml l oxylines. Four fringes where oxygen concentrations were equal or lower than these concentrations were obtained, extending from the southern Gulf to about 28°-28°30′N. A total of 172 sampling locations with squat lobsters were plotted on four maps, one for each fringe, noting that with decreasing values of bottom oxygen ( i.e., from 0.50 to 0.05 ml l) the number of locations with species included between the upper and lower boundaries of these fringes decreases as follows: 34% for 0.50, 25% for 0.25, 12% for 0.10, and 5% for 0.05 ml l. The upper and lower limits of the 0.05 ml l fringe are recognised as threshold frontiers, acting as barriers between shallow and deep communities of squat lobsters in the area. The distribution of the localities where species have been collected with respect to the upper and lower boundaries of the 0.05 ml l fringe clearly indicates a segregation pattern. Eight species of Munida (except M. perlata), and one each of Janetogalathea and Gastropthychus inhabit the shallow area, just above the OMZ core, with species of Munida generally found a rather long distance from this fringe. By contrast, species of Munidopsis, G. diomedeae and U. pubescens correspond to the deep area, i.e., below the OMZ core. It is suggested that the core of the OMZ in the Gulf of California serves as a vertical and latitudinal distribution filter, preventing species from freely migrating up and down or south and north. [ABSTRACT FROM AUTHOR]

To characterize red squat lobster (Pleuroncodes monodon) and yellow squat lobster (Cervimunida johni) aggregations a towed video system was used to cover a seabed area in the Coquimbo region, Chile. The films were made in 2009 and 2010, at depths between 102 and 215 m. Estimated average densities of P. monodon and C. johni varied between 3 and 63 ind m-2 and between 0.2 and 2.8 ind m-2, respectively. Mating couples of C. johni were observed on July 2009 (~ 200 m depth). The results show that the towed video system is an effective means of recording specimens of both species, allowing both the quantitative characterization of the stock and the observation of the species behavior and habitat. The system has the potential for use in direct assessment of abundance and habitat characterization both biotic and abiotic. [ABSTRACT FROM AUTHOR]

Abstract: The reproductive potential of a population depends on the number of broods that individuals produce during the annual reproductive season. Determining the annual brood number is especially relevant for species that are actively fished. Herein we combined different approaches to estimate the annual brood number of two commercially exploited species of squat lobsters from the Chilean continental shelf and upper slope, Cervimunida johni and Pleuroncodes monodon. Long-term maintenance in the laboratory revealed that most females (>70%) produced 3 or more broods during the annual reproductive season. Incubation of individual broods required about 40 days, which would allow for 3 subsequent broods during the main reproductive period (June–September). The dynamics of brood release of ovigerous females that were collected from the field at approximately monthly intervals supported the estimate of 3–4 annual broods for adult females. Furthermore, these latter data also indicated a high degree of breeding synchrony among reproductive females. It is suggested that the production of successive broods might be an adaption to the variable oceanographic conditions during the reproductive period, ensuring that at least one larval cohort finds favorable conditions for development and settlement. Based on these results it is recommended that fishing effort is reduced during the main reproductive period of the two squat lobsters. [Copyright &y& Elsevier]

Abstract: Galatheoids, squat lobsters, have recently received much systematic attention. We describe, discuss, and illustrate ten species of galatheoids found in the mid-Cretaceous (Albian/Cenomanian) Aldoirar patch reef in northern Spain. All are found in the abandoned Koskobilo quarry. The new taxa include two new genera, Hispanigalathea gen. nov. and Nykteripteryx gen. nov., and four new species: Hispanigalathea pseudolaevis sp. nov., H. tuberosa sp. nov., Nykteripteryx rostrata sp. nov., and Eomunidopsis aldoirarensis sp. nov. We redescribe E. navarrensis, E. orobensis, Paragalathea ruizi, P. straeleni, and P. multisquamata. Finally, an indeterminate galatheoid is also recognized. To date, this is by far the richest galatheoid fauna known in terms of the number of species and genera from the Cretaceous, both on the locality and formation level. This diversity is probably related to the reef facies in which the galatheoids were discovered. [Copyright &y& Elsevier]

The reproductive biology of many species of anomuran crabs is only poorly known. Herein we studied the reproductive biology of two species of squat lobsters, Cervimunida johni Porter, 1903 and Pleuroncodes monodon (H. Milne Edwards, 1837), which are target of a trawl fishery operating on the continental margin along the Chilean coast. During the reproductive period (May-November) we maintained squat lobsters in the laboratory to examine whether mating is related to the reproductive molt of the female and to determine the interbrood interval between successive broods. In both species females mated during the intermolt period. Females became receptive shortly after having released larvae from a previous brood, when they formed pairs with males. The interbrood interval (from larval release until having a subsequent brood) lasted <72 hour in the majority of female C. johni, but was longer in P. nionodon, where most females took 72-144 hours before producing a new brood. Despite longer interbrood intervals, copulatory mate-guarding was substantially shorter in P. monodon than in C. johni. These differences in reproductive behavior might be due to differences in the general biology of the two species, including mobility and intraspecific aggression. Mating during the intermolt period may have several advantages, namely reducing the risk of cannibalism and energy costs of molting during the reproductive season. [ABSTRACT FROM AUTHOR]

To better understand the population dynamics of fishery resource species, 160 zooplankton samples were obtained with a Bongo net at 40 oceanographic stations around Caldera and Coquimbo in October and December, 2005, and analyzed. All crustacean decapod larvae were sorted, and Heterocarpus reedi, Cervimunida johni, and Pleuroncodes monodon larvae were identified. For all three species, the highest abundances of early zoea were found in October in Coquimbo, whereas advanced larval stages were predominant in December. In Caldera, advanced larval stages of H. reedi and P. monodon, and early zoeas of C. johni were dominant during both sampling months. The frequency of occurrence of H. reedi larvae was similar during both sampling months in Coquimbo and greater in October in Caldera. The frequency of occurrence of the larvae of P. monodon and C. johni was greater in both areas in October. All the megalops captured in both zones and sampling months corresponded to a single morphotype, with morphological characteristics similar to the smallest P. monodon juvenile specimens. Based on the larval distribution and abundance of these three spe- cies, it is postulated that spawning occurs earlier in the Caldera area than around Coquimbo, mainly in areas near the coast, given the differences in abundance of the developmental stages. [ABSTRACT FROM AUTHOR]

This study was carried out to test the hypothesis that benthic communities on seamounts are distinct from those of other deep-sea habitats at comparable depths. Analysis of the squat lobster fauna of deep-sea habitats in the Southwestern Pacific revealed that the species composition of assemblages on seamounts was not statistically dissimilar from assemblages on slope and plateau habitat at comparable depths. However, compositional differences were observed between seamount and rise and ridge habitat. Differences in assemblage composition between seamount and ridge habitat were statistically significant for two of the four ridge systems examined. Assemblages on seamounts that were distinct from non-seamount ridge habitat were typically dominated by small-bodied species with an abbreviated larval stage. Various environmental variables were correlated with the observed assemblage patterns observed; depth-related variables may account for differences between seamount and rise assemblages, whilst differences in POC flux likely play a role in determining the assemblage compositional patterns between seamount and non-seamount ridge habitat. Extensive pre-analysis data treatment was required to ensure that multivariate analyses of assemblage data from seamount and non-seamount habitats were robust. Our results confirm the findings of recent studies that found no compositional differences in assemblages from seamount and slope habitats, and support the idea that dissimilarity between seamount assemblages on different ridge systems increases with geographic distance. Further research will be required before the generality of these findings can be confirmed. [ABSTRACT FROM AUTHOR]

Abstract Eumunida pictaSmith, 1883, was considered for over a century an amphi-Atlantic species and the only representative of the genus in the Atlantic Ocean, until being split into three species: E. picta sensu stricto (from the northwestern Atlantic), E. bellade Saint Laurent & Macpherson, 1990 and E. squamiferade Saint Laurent & Macpherson, 1990 (from the northeastern and southeastern Atlantic, respectively). Eumunida is now expanded to include a new species, E. notialis, from off the Brazilian coast. Hence, this is the first record of Eumunida and Eumunididae from the southwestern Atlantic. The new species differs from all its Atlantic counterparts in having (1) four hepatic spines; (2) two carapace inframarginal spines; (3) the distal end of the antennal acicle nearly reaching to the articulation between fourth and fifth antennal segments; and (4) the anterolateral spine of the second pleonal tergite obsolete.