Taxonomy & naming
Teleocichla gephyrogramma was described by the Swedish ichthyologist Sven O. Kullander in 1988, in the same Copeia paper that established the genus Teleocichla itself — 'Teleocichla, a new genus of South American rheophilic cichlid fishes with six new species' (Copeia 1988(1): 196–230). The holotype (IRSNB 647, with two paratypes IRSNB 648) is housed in the Royal Belgian Institute of Natural Sciences in Brussels, and the type locality is the Cachoeira von Martius, a set of rapids on the upper Rio Xingu near the boundary of the Brazilian states of Mato Grosso and Pará. The original material had an unusual history: the first Teleocichla specimens were collected in 1964 by King Leopold III of Belgium and the Belgian ichthyologist Jean-Pierre Gosse on the upper Xingu, and lay preserved in Brussels for nearly two decades until Kullander 'rediscovered' them for his revision of South American cichlids. Kullander built the genus name to flag two relationships at once — 'Teleo-' to mark the striking morphological parallel with the African rheophilic genus Teleogramma, and '-cichla' to signal phyletic kinship with the pike cichlids of Crenicichla. That kinship was taken literally by Ploeg (1991), who synonymised the genus and treated this fish as Crenicichla gephyrogramma; subsequent workers (Zuanon & Sazima 2002; Kullander in Reis et al. 2003; Varella and colleagues 2013–2023) rejected the lumping, and Teleocichla is now universally accepted as a valid genus within the eartheater tribe Geophagini. Of the original six species, gephyrogramma was one of three — alongside the type species Teleocichla centrarchus and the more slender T. monogramma — collected at the Cachoeira von Martius.
Morphology
This is a small cichlid: FishBase lists a maximum of 2 in standard length, and even the largest species Kullander described in 1988 (Teleocichla cinderella) reached only about 3 in SL, so a gephyrogramma over 2 in is a large one. The body plan is the genus signature — elongate, only slightly tapered, moderately compressed from side to side, with a short downturned snout and a small mouth. That mouth is the key functional departure from Crenicichla: rather than the wide gape of a piscivorous pike cichlid, Teleocichla has a small terminal mouth built for picking tiny food items off rock, a configuration field observers have likened to the marine dragonets (Callionymidae). The pelvic fins are distinctive — long, relatively stiff, with the middle ray longest and the outer margin somewhat thickened, all consistent with a fish that uses its fins to grip and balance against current rather than to cruise open water. Among the smaller Xingu congeners, gephyrogramma is the comparatively deeper-bodied and stouter of the pair, set against the noticeably slimmer T. monogramma with which it shares a similar underwater colour pattern. Coloration is muted — a cryptic grey-brown ground that matches the rock, with territorial adults flushing more contrast and extending the unpaired fins. The epithet points to the diagnostic mark: the two lateral lines run close together and appear 'nearly united, or bridged,' giving the impression of a single bridging line along the flank. Sexual dimorphism in this genus is subtle; ripe females broaden in the body, and the most assertively coloured, fin-flaring individuals on a territory are typically dominant males, but the sexes are not strongly divergent in pattern.
Habitat
Teleocichla gephyrogramma is a Rio Xingu endemic, part of the Amazon basin in central Brazil. It was described from the upper Xingu at the Cachoeira von Martius and ranges down through the middle and upper river, with the IUCN assessment also recording it from the Rio Iriri, the Xingu's largest tributary. The whole genus is tied to the same biotope: the rocky rapids, cataracts and swift stony-bedded stretches (locally called pedrais and corredeiras) that punctuate these clearwater Brazilian-shield rivers. Teleocichla species are obligate rheophiles — they have effectively traded open-water swimming for a life clamped to rock in fast, oxygen-rich, warm water, and gephyrogramma in particular holds tightly to a territory in the rapids and is rarely seen far from cover. The Xingu is a clearwater river: transparent, soft and warm. Field water chemistry recorded in the rapids near Altamira during the September low-water season ran around pH 6.5, with carbonate and general hardness both near 1° and conductivity about 120 microsiemens — very soft, gently acidic water. Temperatures are high and can be extreme in shallow low-water pools: measurements of roughly 90 °F in the main flow and up to 95 °F in the most exposed shallows have been logged, and FishBase gives a working range of about 79–91 °F. Depth in the inhabited zone is shallow — the rocky areas where Teleocichla were found were on the order of a metre deep at low water, deepening and accelerating through the high-water season.
Feeding
Everything about the genus points to a small-prey, rock-grazing diet rather than predation. The reduced, dragonet-like mouth is unsuited to taking large items, and this is regarded as the very innovation that let Teleocichla exploit the rapids without competing head-on with the predatory rheophilic pike cichlids that share the same water. No detailed gut analysis of gephyrogramma has been published — Kullander himself noted that essentially no observations had been made of the genus in nature at the time of description — but the consensus from morphology and in-situ observation is that these fish pick small invertebrates from the algal and detrital film (aufwuchs) coating the rocks, and probably also snatch drifting plankton and small crustaceans from the current while peering out of crevices. The larger Xingu congeners have been found with the shells of tiny rock-dwelling snails in their guts, reinforcing the picture of a benthic micro-invertebrate forager that works the surfaces of stones. FishBase places the genus at a modest trophic level near 3.1, consistent with an invertebrate-feeder rather than a fish-eater. In the rapids community gephyrogramma is therefore a small-scale benthic grazer of the rock surfaces, one of several Teleocichla partitioning that niche by microhabitat and behaviour.
Mating
Teleocichla gephyrogramma is described from field observation as strongly territorial, holding and defending a patch of rock in the rapids; observers reported never seeing two individuals together, in contrast to the looser, more gregarious congeners. In the related, better-watched species of the genus, a territory typically centres on a particular stone, crevice or hole, with a dominant adult — usually a fin-flaring, more brightly coloured male — occupying it, and smaller, plainer individuals (juveniles and presumed females) sometimes tolerated within or near it. Reproductive isolation among the several Teleocichla sharing the same rapids appears not to rely on segregating into different microhabitats — up to three species have been seen under a single large flat stone — but on behavioural barriers such as courtship signals, coloration and possibly differences in breeding timing. The specifics of pair formation in gephyrogramma have not been documented; what is on record is a fish that defends rock-bound space tenaciously and is intolerant of conspecifics outside a breeding context.
Breeding
Wild breeding of Teleocichla gephyrogramma has not been described in detail, and the species has only rarely reached aquarists, so direct spawning accounts are scarce. Its reproductive biology is inferred from the genus, which comprises cave and crevice substrate spawners: like their Crenicichla relatives and the convergent African rheophiles, Teleocichla deposit their eggs on a hidden surface inside a hole or beneath a stone in the current, with the female tending the clutch in the sheltered cavity while a parent guards the immediate territory. Clutches in fishes this small are correspondingly small — congeneric and comparably sized rheophilic cichlids lay on the order of tens of eggs rather than the hundreds typical of larger open substrate spawners — and parental care is expected to be biparental-to-maternal cave guarding of eggs and wrigglers until the fry are free-swimming. Kullander noted a gravid female of the type species at under 2 in SL, underlining how early these tiny fish mature. Reliable, quantified breeding data specific to gephyrogramma remain unpublished, and any figures should be read as genus-typical inference rather than measured values for this species.
In the aquarium
Teleocichla gephyrogramma is very much a specialist's fish and is only occasionally available; it is not a beginner subject and has no settled track record in the hobby comparable to mainstream Crenicichla. The whole point of keeping it is to recreate the rapids: a tank built around strong, well-oxygenated flow over a hardscape of smooth water-worn stones and cobbles, with caves, crevices and overhangs that give each fish a defensible retreat. Powerheads or a river-manifold to drive brisk current, vigorous filtration and pristine, oxygen-saturated water are essential — these fish come from turbulent, high-oxygen torrents and do poorly in still, warm, organically loaded tanks. Water should mirror the Xingu: soft, low in carbonates, gently acidic to neutral (around pH 6.0–7.0), and warm, with 79–86 °F a sensible maintenance window even though the wild fish tolerate brief excursions into the low-to-mid 30s in shallow pools. Given the small adult size, a modest footprint can house a fish or a small group, but the fierce intraspecific territoriality means broken sightlines and plentiful separate caves are critical — in too little rockwork a dominant individual will monopolise the space and harass the rest. Tankmates should suit the same fast, hard-bottomed biotope: other rapids fishes that can hold their own without crowding the rock, kept lean rather than packed. Feeding is the practical hurdle — the small mouth is made for tiny prey, so live and frozen micro-foods (small crustaceans, bloodworm, cyclops) and finely graded sinking foods work best, offered into the current where the fish can dart out and snatch them. Keepers who fail with the genus usually do so on flow, oxygen and water quality, not on temperament.
Conservation
The IUCN Red List assesses Teleocichla gephyrogramma as Least Concern (assessed 7 November 2018, published 2022, by the Instituto Chico Mendes de Conservação da Biodiversidade, ICMBio), with population trend listed as unknown. The Least Concern rating rests on the species being distributed through the middle and upper Xingu and into the Rio Iriri rather than confined to a single rapid, but the assessment is explicit about the looming pressure: the genus's obligate dependence on rapids habitat makes it acutely vulnerable to dams and water management, and the Belo Monte hydroelectric complex on the lower Xingu is named as the principal threat. Belo Monte diverts a large fraction of the river's flow around the so-called Volta Grande (Big Bend), dewatering and disrupting the very rocky-rapids microhabitats — the calm-flow refuges, oxygen regimes and seasonal flood pulses — that rheophilic cichlids depend on, and it has already destroyed the type locality of the congeneric Teleocichla cinderella on the dammed Tocantris-basin sister river (and the Tucuruí dam earlier did the same elsewhere in the genus's range). For a clade of small, current-bound, narrowly habitat-specialised fishes, river regulation is the existential issue, and the conservation outlook for gephyrogramma should be read against the continuing alteration of Xingu flow rather than against its present, comparatively reassuring Red List category.