Temnosewellia semperi (Platyhelminthes: Temnocephalida) from Maydelliathelphusa lugubris (Arthropoda: Gercarcinucidae) of the state of Meghalaya, North East India

Abstract

: Temnocephalids are rhabdocoel flatworms that are found either commensal or parasitic on a wide variety of hosts. In India, the occurrence of temnocephalids was recorded and studied from preserved specimens. Regarding the morphology of the specimens, vague descriptions were given. Since then, no following studies were found. This study provides a new insight regarding the specimens found on a freshwater crab, Maydelliathelphusa lugubris (Wood-Mason, 1871). The specimens are identified as Temnosewellia semperi (Weber, 1890) based on the presence of brown pigment, five tentacles, posterior adhesive disc, five syncytial plates: tentacular, postentacular, body, peduncular and adhesive plates, the excretory pore lying on the dorsal side of the body plate and the absence of papillae on the dorsal surface or tentacular surface. The most important diagnostic feature is the structure of the cirrus which is the main taxonomic character to identify the species. Temnosewellia semperi has a nearly straight cirrus with the distal part slightly dilated as observed in this species.