Taxonomy & naming
Lentipes venustus is a true goby of the family Oxudercidae, placed in the Sicydiinae, the amphidromous stream gobies of Indo-Pacific islands. The Catalog of Fishes lists it as valid under the authority Allen, 2004. The type locality is given there as: Tuaneda River, 9°23'01.5"S, 150°19'32"E, near Kalauma Village, Goodenough Island, Milne Bay Province, Papua New Guinea, elevation 1,148 ft.
Morphology
Sicydiine gobies have the pelvic fins fused into a cup-shaped sucker disc, which lets them hold position on rock in fast current and climb wet rock faces on the way upstream. Males in this group are usually more colourful than females. FishBase gives a maximum of 1.5 in SL for this species. It is usually seen resting on the bottom, attached to rock by its pelvic sucker.
Habitat
FishBase says the species occurs in mountainous terrain in cool, clear, fast-flowing streams at elevations from about 100 to at least 1,969 ft, collected at depths of roughly 2–4 ft. It is listed as freshwater and demersal, at 22 to 24 C, and is known from the D'Entrecasteaux Islands in Milne Bay Province.
Feeding
Lentipes species are generally regarded as carnivores that take small invertebrates and insect larvae from the stream bed. The diet of this species has not been described specifically.
Mating
Mating has not been described for this species. In better-studied sicydiines, males hold small territories on stream rock and court females at a nest site.
Breeding
Sicydiine gobies are amphidromous: eggs are laid in fresh water, the larvae drift to sea, and the post-larvae return to rivers months later. Details specific to this species have not been published. It cannot be assumed to breed in a closed freshwater aquarium, and trade fish are wild-collected.
In the aquarium
Species in the trade under this name are demanding. They need cool to moderate, very clean, strongly oxygenated water, brisk flow, rock surfaces with mature biofilm, and a tightly closed lid. Husbandry for Lentipes venustus itself has not been documented, so general sicydiine practice is the only guide. Identity of fish sold under this name should be treated with caution. The FishBase temperature of 22 to 24 C points to cool water.
Conservation
The IUCN assessed Lentipes venustus as Least Concern in 2020, meaning it is not currently considered at risk. Like other amphidromous gobies, it depends on unobstructed streams down to the sea, and dams, weirs and stream degradation are threats to the group.