Goezia nankingensis Hsü, 1933 (Nematoda: Raphidascarididae) from the critically endangered Chinese paddlefish Psephurus gladius (Martens) (Acipenseriformes: Polyodontidae)

Abstract

Goeziine nematodes identified as Goezia nankingensis Hsü, 1933 were collected from the Chinese paddlefish Psephurus gladius (Martens) (Acipenseriformes: Polyodontidae), a critically endangered freshwater fish, from the Yangtze River in China. Their examination, using light microscopy and, for the first time, scanning electron microscopy, revealed some erroneous and previously unreported morphological features, necessitating the redescription of this poorly known species. Goezia nankingensis is easily distinguished from its congeners by the morphology and arrangement of its cuticular spines, the short intestinal caecum and long ventricular appendix (ratio of intestinal caecum to ventricular appendix 1:10.0-18.3), the short spicules (0.34-0.49 mm long, representing 6.09-10.1% of the body length), the number and arrangement of male caudal papillae [14-16 pairs in total, approximately arranged: precloacal 7-10 pairs, paracloacal 2 pairs and postcloacal 4-6 pairs (one pair double)], and the presence of a particular medio-ventral, precloacal papilla in the male.

Hysterothylacium gibsoni sp. nov. and H. tetrapteri (Bruce et Cannon, 1989) (Nematoda: Ascaridida) from the Chinese marine fishes

“…Nematodes recovered from the digestive tract of various fishes were washed in physiological saline and then fixed and stored in 80% ethanol until studied. Light and scanning electron microscopical studies were prepared following the methods used by Li et al (2012c). Drawings were made with the aid of Nikon microscope drawing attachment.…”