3a. Dorsal-fin height greater than length of head; pectoral-fin margin angular; nasal barbel extends well beyond opercular margin
.....................Paraplotosusbu tleri
(northern and western Australia, from Shark Bay to the Gulf of Carpentaria)
3b. Dorsal-fin height less than, or equal to, length of head; pectoral-fin margin rounded;
nasal barbel not extending beyond opercular margin, often falling far short of margin
4a. Dorsal fin short, its height 50 to 70% of head length; eye small, its diameter 5 or more
times in head length.............................Paraplotosusalbilabris
4b. Dorsal-fin height 75 to 100% of head length; eye larger, its diameter 4 times or less in head length ..................................Paraplotosusmu elleri
(northern Australia, from Dampier Archipelago to the Gulf of Carpentaria)
5a. Nasal and maxillary barbels long, reaching at least to pectoral-fin base; body uniform in colour, without stripes; total fin rays in confluent median fins 247 to 281
......Plotosuscanius
5b. Nasal and maxillary barbels short, reaching to, or only slightly past, posterior margin of eye; body usually with 2 or 3 whitish stripes, 2 of which extend onto head; total fin rays in confluent median fins 139 to 200