Microlaimidae (Microlaimoidea: Nematoda) from the Indian Ocean:

Abstract

Nine species are described from the genera Aponema Jensen, 1978, Bolbolaimus Cobb, 1920, Calomicrolaimus Lorenzen, 1976, Ixonema Lorenzen, 1976 and Microlaimus de Man, 1880. Aponema decraemerae sp.n.is characterised by sexual dimorphism in the size of the amphids, short cephalic sensilla, spicules with a poorly developed capitulum and conical cylindrical tail with a pointed tip. Aponema mnazi sp.n. is characterised by short cephalic sensilla, head set off from the rest of the body by a fine constriction, spicules with a pointed anterior tip, one precloacal supplement located at 7 µm from the cloaca opening and a short tail with a blunt tip. Bolbolaimus bahari sp. n. is characterised by cuticular annules with fine interannular spaces, papilliform labial sensilla and short setiform cephalic ones, curved spicules with a poorly developed capitulum. Bolbolaimus abebeisp.n.ischaracterisedbysetiformouterlabialandcephalicsensillaandspiculeswithawell-developedbeak shaped capitulum. Calomicrolaimus jenseni sp. n. is characterised by an elongate cervical region, small (2µm wide) amphidslocated at 44–54%of the pharyngeallength from the anterior and a conical tail with a pointedtip. Ixonema deleyi sp. n. is characterised by a small body (<400µm long) an elongate cervical region, small (1–2 µm wide) circular amphids with rod-like corpus gelatum located at 30–45% of the pharyngeal length from the anterior. Microlaimus texianus Chitwood, 1951 is characterised by sexual dimorphism in the size of the amphids andpresenceoffive pre-cloacalsupplements.Microlaimusminutussp. n. is characterisedbya small body(< 300 µm long) that is often curved or coiled, amphids that are 55–60% cbd and located at 11–15µm away from the anterior end and short (12–15µm long) simple spicules. Microlaimus pwani sp.n. is characterised by prominent cuticularannules,longcephalicsensilla,amphidsthatare50–55%cbdandlocatedat11–13µmfromtheanterior endandlongsausage-shapedstriated sperms.