Pygmy Possum Wrasse Breeding Guide (Wetmorella nigropinnata)
Wetmorella nigropinnata is a tiny, secretive cave-dwelling wrasse recorded only as an oviparous pair-spawner with little documented reproductive biology; it is not home-bred, and this guide notes what is actually known.
Overview
The pygmy possum wrasse (Wetmorella nigropinnata) is a tiny Labridae wrasse of the subfamily Cheilininae, reaching only about 8 cm in total length. It has a wide Indo-Pacific range from the Red Sea to the Marquesan and Pitcairn islands, north to the Ryukyu Islands and south to the southern Great Barrier Reef and New Caledonia, at depths of 0 to 36 m. It is a secretive species inhabiting caves and crevices on lagoon and seaward reefs.
Sexing
No external sexing key is documented for this species in the consulted sources. Its reclusive, cave-dwelling habits mean it is rarely observed even in the wild, and FishBase provides no dimorphism data, so reliable visual sexing cannot be described.
Spawning Behavior & Trigger
FishBase records the species as oviparous with distinct pairing during breeding. Beyond this pairing behaviour, no specific spawning sequence, site preference or trigger is documented for Wetmorella nigropinnata in the consulted sources, and no captive spawning has been reported.
Egg & Fry Care
The consulted sources do not document egg type, larval form or any fry-rearing information for this species. As a small reef labrid it is presumed to follow the general oviparous wrasse pattern, but specific data are absent, so no rearing guidance can be given.
Common Challenges
Its extreme shyness, tiny size and reliance on dark caves and crevices make even routine observation difficult, and the absence of documented reproductive detail means there is no basis for a captive breeding attempt. It remains a wild-collected species in the aquarium trade.