A new species of cave crab, Stygothelphusa antu new species, is described from limestone formations in Temurang, Sarawak, Malaysia. The new species is the most highly adapted to a cavericolous lifestyle among the four known species of Stygothelphusa, having a pale body pigmentation, reduced eyes and elongated pereopods. In contrast, the other three species have normal eyes that almost completely fill the orbits. The new species also differs from its congeners by a number of carapace, pereopod and gonopod characters.
The identity of the common lowland freshwater crab in western Sarawak, Borneo, East Malaysia, Parathelphusa oxygona Nobili, 1901 (family Gecarcinucidae), is clarified. The species is redescribed and figured, and its taxonomy discussed. Specimens from western Kalimantan, Borneo, Indonesia, which have been referred to P. oxygona are here referred to a new species, Parathelphusa nobilii. The new species can be differentiated from congeners by its relatively more swollen branchial regions of the carapace, wider and lower external orbital tooth, relatively more slender male abdomen and a straight male first gonopod.
The male of Hexapinus latipes (De Haan, 1835), so far known only from female specimens, is described based on the material reported by De Man (1888) as "Hexapus sexpes". Material referred to "Hexapus sexpes" by Tesch (1918) is shown instead to belong to Hexapinus simplex Rahayu & Ng, 2014, and Hexapinus latus Rahayu & Ng, 2014, while his "Hexaplax megalops Doflein, 1904" belongs to Hexaplax aurantium Rahayu & Ng, 2014. A new species, Mariaplax aspera n. sp., is described from a female collected in Lombok, Indonesia. This new species most closely resembles M. narusei Rahayu & Ng, 2014, described from Japan, but differs by its relatively narrower carapace, shorter ambulatory legs, tuberculated third maxillipeds, and shorter telson.
A new species of terrestrial sesarmid crab, Scandarma raymondi, is described from Sabah, Malaysia. This is the third species in the genus; others are from Taiwan, Japan and Sarawak, Borneo. The new species differs from congeners in the live coloration, proportions of the carapace and ambulatory legs and morphologies of the male abdomen, chela and male first gonopod.
A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters.
A recent rise in crab aquaculture activities has intensified the generation of waste shells. In the present study, the waste shells were utilized as a source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shell is calcium carbonate which transformed into calcium oxide when activated above 700 degrees C for 2 h. Parametric studies have been investigated and optimal conditions were found to be methanol/oil mass ratio, 0.5:1; catalyst amount, 5 wt.%; reaction temperature, 65 degrees C; and a stirring rate of 500 rpm. The waste catalyst performs equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to 11 times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity.