Taxonomy & naming
Glossogobius matanensis was described in 1913 by Max Wilhelm Carl Weber, the German-Dutch zoologist whose extensive surveys of the Indonesian archipelago's freshwater and marine fauna, often conducted as part of the Siboga Expedition and related work, first documented much of the extraordinary endemism of Sulawesi's ancient lakes. The specific epithet matanensis is a toponym referring to Lake Matano, the species' type locality. Eschmeyer's Catalog of Fishes lists Glossogobius matanensis (Weber, 1913) as a valid species within the family Oxudercidae, genus Glossogobius.
Lake Matano, part of the Malili Lakes complex in central Sulawesi along with Lake Towuti and Lake Mahalona, is renowned among freshwater biologists as one of the world's oldest and deepest lakes, comparable in some respects to Lake Baikal or the African Rift lakes for its degree of in-situ evolutionary radiation across multiple unrelated animal groups.
Morphology
As with other Glossogobius, G. matanensis is expected to show the genus's characteristic elongate body, broad flattened head and fused pelvic-fin sucker disc typical of true gobies. Detailed published morphometrics and colour-pattern description specific to this species were not confidently available from the sources consulted here — data sparse, reflecting the comparatively limited modern literature on Lake Matano's less conspicuous endemic fish relative to its famous sailfin silversides.
Habitat
Glossogobius matanensis is endemic to Lake Matano, an exceptionally deep, clear and oligotrophic (nutrient-poor) tectonic lake in central Sulawesi, Indonesia, reaching depths in excess of 500 metres and considered one of the ten deepest lakes on Earth. As a benthic goby it presumably occupies the lake's littoral and substrate zones, where rocky and sandy bottoms provide cover and foraging habitat, though the precise depth range and specific microhabitat use were not confidently available from the sources consulted here — data sparse.
Lake Matano's water is notably clear and stable in temperature, a product of its great depth and the surrounding forested, largely undisturbed watershed — conditions very different from the warm, turbid rivers most Glossogobius species elsewhere in their range inhabit.
Feeding
No dedicated dietary study of Glossogobius matanensis has been located. As with other Glossogobius, an opportunistic carnivorous diet of small fish and benthic invertebrates is inferred from the genus rather than confirmed directly for this species.
Mating
Courtship and spawning behaviour specific to Glossogobius matanensis have not been documented in the sources consulted. Glossogobius generally are demersal nest-guarders: males typically defend a burrow, crevice or the underside of a rock or shell as a spawning site, where the female deposits adhesive eggs that the male then guards and fans until hatching — a pattern presumed but not directly confirmed for this species.
Breeding
No published account of captive breeding specific to Glossogobius matanensis was located. As with other Sulawesi lake-endemic gobies, it is plausible the species completes its full life cycle within fresh water without a marine larval-dispersal phase, in contrast to many amphidromous true gobies elsewhere, but this has not been directly confirmed here — data sparse.
In the aquarium
Glossogobius matanensis is not established in the aquarium trade, and any captive-husbandry information specific to it is data sparse. Given the exceptional conservation value of Lake Matano's endemic fauna, any specimens encountered should be treated with particular care regarding sourcing and provenance. General husbandry for Sulawesi lake-endemic fish typically favours clean, well-oxygenated, stable and moderately cool-to-warm water reflecting the deep, clear, thermally stable lake environment these species evolved in.
Conservation
Glossogobius matanensis is listed by the CARES Preservation Program at the Near Threatened (CNT) priority level. Lake Matano and the wider Malili Lakes system face growing environmental pressure from nickel mining and associated laterite ore processing in the surrounding watershed, which brings risks of sedimentation, altered runoff, and water-quality change to lakes whose endemic fauna evolved under exceptionally stable, clear, oligotrophic conditions. The introduction of non-native predatory fish species into the Malili Lakes has also been documented as a threat to native fauna elsewhere in the system. As a narrow-range lake endemic, G. matanensis is presumed vulnerable to these same pressures even though a species-specific population assessment was not confirmed from the sources consulted here.