The high prevalence (80-100%) of the marine leech Zeylanicobdella arugamensis (De Silva) on cage-cultured Asian sea bass Lates calcarifer (Bloch) led us to investigate the percentage of juvenile leeches hatched from deposited cocoons, survival of juvenile and adult marine leeches at different salinity and temperature. The results showed that the hatching percentage of juvenile leeches was highest at salinity of 30 ppt (32.5 ± 2.8%) followed by 20 ppt (18.0 ± 4.3%) and 10 ppt (12.1 ± 1.4%), respectively. It was found that the adult and juvenile leeches could live up to an average range of 4-7 days at salinity ranging from 10 to 40 ppt. The juvenile leeches were able to hatch at temperature ranging from 25 to 35 °C but unable to hatch at 40 °C. The survival period of adult and juvenile leeches ranged from 11 to 16 days at 25 °C, which was comparatively longer than 5-13 days and 10 h--5 days at 27-30 °C and 35-40 °C, respectively. The study provided the information on the physical parameters of salinity and temperature which are most optimal for the marine leech Z. arugamensis to propagate.

A bopyrid isopod was found attached in the gill chamber of a wild giant freshwater prawn, Macrobrachium rosenbergii (De Man, 1879) from the Timun River, Negeri Sembilan (Malaysia) (2 • 28 N 102 • 02 E), with a prevalence of 0.27% (2/743). The specimens measured 18.25 ± 0.35 mm in length and 15.25±0.35 mm in width. The body of the isopod was subcordate and slightly distorted. It has five oostegites, with black pigment. The first oostegites are large, the 2 nd and 3 rd are suboval and smaller, while the 4 th and 5 th are long and ending in sharp points. Both specimens were identified as adult female Probopyrus buitendijki (Horst, 1910). The isopod was found only in January of 2009 and 2010, which months recorded a relatively low rainfall. A histopathological study of the infected gill showed impairment of the gill filaments, necrosis, and hyperplasia. Such effects may reduce the respiration efficiency of the gills. RÉSUMÉUn isopode Bopyridae a été trouvé fixé dans la chambre branchiale de la crevette géante d'eau douce, Macrobrachium rosenbergii (De Man, 1879) de la rivière Timun, Negeri Sembilan (Malaisie) (2 • 28 N 102 • 02 E), avec une prévalence de 0.27% (2/743). L'isopode mesurait 18,25 ± 0,35 mm de long et 15,25 ± 0,35 mm de large. Le corps de l'isopode était subcordiforme et légèrement déformé. Il possède cinq oostégites, avec un pigment noir. Les premières oostégites sont de grande taille, les 2èmes et 3èmes sont de forme subovale et plus petites, tandis que les 4èmes et 5èmes sont longues et terminées en pointes aigües. Les spécimens ont été identifiés comme des femelles adultes de Probopyrus buitendijki (Horst, 1910). L'isopode a été trouvé seulement en janvier 2009 et 2010, mois présentant des précipitations relativement basses. Une étude histopathologique de la branchie infectée s'a révélé une détérioration des filaments branchiaux, une nécrose et une hyperplasie. De tels effets pourraient réduire l'efficacité de la respiration des branchies. 1 )