Series:

Célio Magalhães, Carola Becker, Peter Davie, Sven Klimpel, Pedro Martínez-Arbizu and Moritz Sonnewald

Series:

Neil Cumberlidge

Abstract

Potamonautes walderi (Colosi, 1924), is redescribed from the lectotype and the male gonopods, abdomen, mouthparts, chelipeds, and sternum are illustrated. Photographs of the lectotype are provided and its distribution and conservation status is discussed. Potamonautes walderi is also compared to the other species of this genus that are found in the Congo River basin in Central Africa.

Series:

Mariana Negri, Tatiana Magalhães, Natália Rossi, Darryl L. Felder and Fernando L. Mantelatto

Abstract

The shrimp Cuapetes americanus is widely distributed in shallow waters of the western Atlantic Ocean, inhabiting sandy and rocky bottoms, macroalgae, seagrass beds, and mangrove roots. As the life cycle and ecology of this species remain poorly known, we investigated some reproductive traits of this species at Bocas del Toro, Panama. We collected and examined 167 individuals (63 males, 58 non-ovigerous females and 46 ovigerous females). Although males numerically dominated the larger size classes, ovigerous females were significantly larger than males and non-ovigerous females. All 46 ovigerous females were used to calculate embryo loss and embryo volume increase. Only females with eggs at an initial developmental stage (n = 25) were used to estimate fecundity and reproductive output. A mean of 75.84 ± 40.16 embryos (Ne = 32-208) occurred per female, a value near those reported for other species of Pontoniinae. A positive correlation between fecundity and female book-body size was observed, but it lacked significance. Likewise, a significant correlation between female body size and embryo volume was not detected. Embryo volume increased 35%, and females lost 26% of embryos on average during the incubation period, though significant changes were measurable only during early embryonic development. Mean reproductive output in the analysed reproductive event (0.22 ± 0.11, R = 0.02-0.53) suggested a rate of energy investment in reproduction higher than average, as compared to females of most other decapods. A decrease in relative reproductive output was observed with the increase of female size, indicating that larger females were investing proportionally less energy in reproduction than smaller ones, when measured in relation to the body size, but this correlation also lacked significance. We review how these initial insights on reproduction of C. americanus at Bocas del Toro compare to those of other populations in various localities.

Series:

Sabrina M. Simões, Gisele S. Heckler and Rogerio C. Costa

Abstract

The aim of this study was to assess whether all Penaeoidea shrimps captured by trawling are protected by the current closed season. We investigated the reproductive period and juvenile recruitment of Penaeoidea shrimp species captured in the bay-estuary complex of Santos and São Vicente from May 2008 to April 2010. Samples were collected monthly using a shrimp boat at four sites in the estuary and four sites in the bay; environmental factors were monitored. The reproductive condition of females was determined by macroscopic observation of gonads. Juvenile and adult males were classified by observing the endopod forming the petasma; the reproductive condition was determined by the presence of spermatophore in the terminal ampoule. A dendrogram showed little similarity in the reproductive periods of the species sampled in this study. The greatest similarity in the recruitment period was in the white shrimp, Litopenaeus schmitti, and the pink shrimps Farfantepenaeus paulensis and F. brasiliensis, species that are protected by the current closed season. Pink shrimps are not fully protected, however, as they are captured indiscriminately in the estuary, to be used as fishing bait. Considering the number of individuals of reproductive females and juveniles, Xiphopenaeus kroyeri was the most abundant in the marine environment, and L. schmitti, F. paulensis and F. brasiliensis were the most abundant in the estuarine environment. The adequacy of the closed season is discussed, including issues such as the implementation of projects focusing on fishermen and the sustainable use of bait; the closure of fishing from October to December in coastal areas with depths below 20 m, and the application of a regional closed season instead of the current law applied in several states.

Series:

Katsushi Sakai

Abstract

Material collected during the Pacific Expedition (1913-1916) under the leadership of Dr. Th. Mortensen was studied. As a result of the examination, Jaxea novaezealandiae Wear & Yaldwyn, 1966 (Laomediidae Borradaile, 1903) and Eucalliax kensleyi Dworschak, 2005 (Callianassidae Dana, 1852, sensu Sakai & Sawada, 2006) are recorded, and Tuerkaygourretia galathea gen. et sp. nov. (Gourretiidae Sakai, 1999) and Garyia sachikoae sp. nov. (Thomassiniidae De Saint Laurent, 1979) are newly described. The family Gourretiidae, reviewed on this occasion, is safely considered to comprise eight genera, including five new ones, Heterogourretia gen. nov., Ivorygourretia gen. nov., Plantesgourretia gen. nov., Ruiyuliugourretia gen. nov. and Tuerkaygourretia gen. nov.

Series:

Martha R. Campos and Diógenes Campos

Abstract

The aim of this paper is to characterize the species diversity of freshwater decapod crustaceans (crabs and shrimps) from Colombia by using a dataset containing 964 digitized records and 13 881 specimens collected between 1910 and 2016, information that has been assembled with data from 21 museums and other institutions worldwide. The characterization of species diversity is based on the estimation of relative abundance of species and it is calculated in three separate analyses in which the data were partitioned as follows: (a) by decapod families (six in Colombia) (b) the unpartitioned dataset of all 139 Colombian species and (c) by the five biogeographic regions in the country. In each case, Campos & Isaza’s species diversity index and the Shannon entropy index were calculated. The calculations performed here also allowed the identification of predominant species and those that are least represented in collections and might therefore be at greater risk of extinction.

Series:

Jose C. E. Mendoza and E. Y. Sy

Abstract

A new species of the freshwater crab genus Sundathelphusa Bott, 1969 (Gecarcinucidae) is described from the island of Mindanao in the southern Philippines. The Philippine Islands host the greatest species diversity of this genus, although only four species were previously known from Mindanao. The new species is most similar to S. mistio (Rathbun, 1904) and S. montanoanus (Rathbun, 1904) in the general carapace outline and leg proportions, but it can be distinguished by features of the carapace, thoracic sternum and gonopods. With this discovery, there are now 29 species of Sundathelphusa known from the Philippines.

Series:

Vassily A. Spiridonov

Abstract

Thalamita matzuzawai sp. n. is described from the subtidal zone of Shikoku, Japan. This species is most similar to Thalamita picta Stimpson, 1858 and T. simillima Crosnier, 2002. It also shows similarity to the group of Thalamita species with a supplementary tooth at the base of the first anterolateral tooth, thus representing an intermediate position between these two groups. Thalamita williami sp. n. is described from Brunei. It belongs to the T. crenata Rüppell, 1830 group and is most similar to T. starobogatovi Tien, 1969.

Series:

Masatsune Takeda and Hironori Komatsu

Abstract

Two new species of the crab genus Actumnus Dana, 1851 (family Pilumnidae) are reported from the Ryukyu Islands, southwest Japan. Actumnus tsurukaii sp. nov. is similar to A. squamosus (De Haan, 1835), A. setifer (De Haan, 1835) and A. forficigerus (Stimpson, 1858) in possessing a poorly defined dorsal surface of the carapace with a coat of short setae, but differs in having relatively larger, fewer and more widely spaced conical granules or tubercles on the outer surfaces of the palms of both chelipeds. Actumnus uformis sp. nov. is similar to A. dorsipes Stimpson, 1858 and A. granotuberosus Garth & Kim, 1983 in having a prominently areolated dorsal surface of the carapace with a soft thick tomentum, but can be distinguished by the stronger areolation and the distinctly U-shaped protogastric region.

Series:

Shane T. Ahyong and Keiji Baba

Abstract

Uroptychus michaeli sp. nov. is described from northwestern Australia and Taiwan. The new species closely resembles U. nigricapillis, to which northwestern Australian and some Taiwanese records had been previously referred. Uroptychus michaeli sp. nov. is readily distinguished from U. nigricapillis by the deeply excavate cervical groove on the carapace (versus shallow, weakly indicated), more elongate pereopods 2-4 in which the pereopod 2 merus is longer than the postorbital carapace length (versus shorter), and the proportionally longer pereopod 2 carpus, which is as long as or longer than half postorbital carapace length (versus less than half) and approximately twice the length of the dactylus (versus 1.2× or less).