Description of Parahadronchus shakili (Mononchida: Nematoda) showing some abnormalities in the buccal cavity with an updated key to species of the genus Parahadronchus

Abstract

Parahadronchus shakili (Jairajpuri, 1969) Mulvey, 1978 is widely distributed in India. The morphometrics of a population showing some abnormalities in the buccal cavity are reported. Both female and male specimens were collected from the district South 24-Parganas, West Bengal, India. Female body 2.74-2.85 mm long; a = 32.9-35.6; b = 4.2-4.5; c = 6.3-7.4; c´ = 7.7-12.8; V% = 65.1-72.8. Gonads double, ovary reflexed, length of ovary less than oviduct length, uterus longer than oviduct, sphincter distinct at oviduct-uterus junction. A few females gravid with 2-4 large intra-uterine eggs. Male body 2.90-3.55 mm long; a = 45.0-53.7; b = 4.8-5.1; c = 8.3-9.7; c´ = 4.7-6.4; PO = 11-15. Female and male specimens generally have four sub-ventral teeth on each of the two sub-ventral walls of the buccal cavity, but a few male specimens from South 24-Parganas showed some variability in their buccal cavity. Their two sub-ventral walls bear 0-5 sub-ventral teeth. Among the eleven described species of the genus Parahadronchus Mulvey, 1978, eight were reported from India. An updated list of species under the genus Parahadronchus and a key to their identification have been included.