Key to the marine species of Plotosidae occurring in the area
1a.
Body very elongate, depth at first dorsal-fin origin less than 11% of standard length
(Fig.
1)
......................................
.
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1b.
Body less elongate, depth at first dorsal-fin origin usually greater than 15% of standard
length (Figs 3 and 4)
.......................................
®
2
2a.
Anterior nostril a round tube situated within folds of upper lip, opening directed ventrally
(Fig. 2); second dorsal-fin origin situated immediately behind first dorsal fin and anterior
to vertical line extending from pelvic-fin origin, appressed first dorsal fin extends past
origin of second dorsal fin; gill membranes joined broadly across isthmus and attached
to isthmus anteriorly
...............................
(
Paraplotosus
)
®
3
2b.
Anterior nostril a round tube situated dorsal to upper lip, opening directed anteriorly;
second dorsal-fin origin posterior to vertical line from pelvic-fin origin, appressed dorsal
fin not reaching origin of second dorsal fin; gill membranes narrowly attached across
isthmus
........................................
(
Plotosus
)
®
5