Taxonomy & naming
The dolphin cichlid was first described by the French naturalist Jean Puyo in 1943, in a paper on new freshwater fishes of French Guiana, under the name Aequidens itanyi — placing it in the large, loosely defined catch-all genus where most South American "acaras" then sat. For nearly half a century it stayed there. In 1989, in their landmark monograph The Cichlids of Surinam, Sven O. Kullander and Han Nijssen erected the genus Krobia to receive two Guiana-Shield species that did not fit comfortably in Acara or Aequidens: Acara guianensis Regan, 1905 and Puyo's Aequidens itanyi. Within Kullander and Nijssen's arrangement Krobia falls in the subfamily Cichlinae, tribe Cichlasomatini — the lineage of medium-bodied Neotropical substrate-spawners that also contains Cichlasoma, Aequidens and Bujurquina. Their work redescribed itanyi in detail (page 166), with a diagnosis, distribution and illustrations, and the combination Krobia itanyi has been accepted ever since by Kullander's own 2003 continental checklist and by subsequent revisers. A neotype (catalogued ZMA 119531 in the Amsterdam collection) anchors the name to a Marowijne River tributary in Suriname's Marowijne District, the type locality. The genus has since grown: Kullander (2012) added Krobia xinguensis from the Xingu in Brazil, and Steele, Liverpool & López-Fernández (2013) described Krobia petitella from the Berbice River in Guyana, so that today Krobia comprises four valid species — three of them Guiana-Shield endemics plus the outlying Xingu form.
Morphology
Krobia itanyi is a compact, moderately deep-bodied acara reaching about 5 in in standard length, with males running a little larger than females. The common name is well earned: the head profile rises in a smooth, rounded curve from a blunt snout, giving mature fish a faintly dolphin-like brow. The ground colour is a warm grey-brown to olive, paler below, overlaid in good condition with a sheen of blue-green to gold iridescence that picks out the scale margins and the cheek. A dark lateral band and a midlateral blotch are typical of the genus, and rows of fine spangled spots can light up the flanks and the unpaired fins when a fish is displaying. The sexes are told apart mainly by the fins and the body: males grow somewhat larger and more colourful, and their dorsal, anal and pelvic (ventral) fins are drawn out into longer points — the trailing pelvic filaments in particular extend back past the origin of the anal fin, a useful field mark for sexing. Females are correspondingly plumper and shorter-finned, especially when ripe. Within the genus, itanyi is separated from its close relative Krobia guianensis and from the Xingu Krobia xinguensis by details of head and jaw markings: it lacks the dark anterolateral jaw spot and the red-orange head-and-trunk marks that distinguish the Xingu fish, for instance.
Habitat
Krobia itanyi is a fish of the Marowijne (Maroni) River drainage, the basin that forms much of the border between Suriname and French Guiana; its specific name comes from the Itany (Litani), one of the Maroni's headwater rivers. The IUCN range also reaches into the adjacent coastal drainages of Amapá in northern Brazil, and its sister species fill out neighbouring Guiana-Shield basins. These are clear, soft, warm tropical waters draining ancient shield rock. Like the other Krobia, it is most abundant in small, slow-flowing, shallow creeks with a mixed rocky-and-silty bottom rather than in big open rivers, and it shares those creeks with a characteristic Guiana fish community — the related cichlid Guianacara owroewefi, the pencilfish Pyrrhulina filamentosa, the headstander-like Cyphocharax spilurus, the tetra Hemigrammus guyanensis and the catfish Heptapterus longior. Collections of close congeners in comparable Guiana-Shield streams record shallow water, often under a metre deep, over muddy or silty substrate in lentic clear-water stretches. The chemistry is the soft, lightly mineralised, gently acidic-to-neutral water typical of shield blackwater and clearwater streams, at warm lowland temperatures; FishBase classes the species as a benthopelagic freshwater tropical fish.
Feeding
In the wild the dolphin cichlid is a benthic micro-predator and opportunistic omnivore, feeding on small crustaceans and aquatic insect larvae gleaned from the creek bottom and the leaf litter, with a calculated trophic level around 3.4 — solidly carnivore-leaning but not a specialist piscivore. Like most cichlasomatines it works the substrate, taking mouthfuls of sediment and detritus and sorting edible invertebrates from the grit, but it is a generalist forager rather than a dedicated sand-sifter. That flexible, invertebrate-heavy diet translates directly to the aquarium, where the species accepts almost anything of suitable size and shows the best colour on a varied menu rich in live and frozen meaty foods. In its native creeks it occupies the middle of the food web: a small predator of invertebrates that is in turn prey for the larger fish, birds and other piscivores of the Guiana streams.
Mating
Krobia itanyi is a pair-bonding, biparental substrate spawner, and its reproductive behaviour follows the classic cichlasomatine template. Outside of breeding it is a relatively peaceable, loosely social fish, but as a pair comes into condition the two fish select and clean a spawning site — typically a flat, exposed stone — and become conspicuously territorial, driving other fish away from the chosen rock and the surrounding patch of bottom. Courtship runs through the familiar repertoire of mutual displays, lateral presentation, fin-spreading and quivering, and trial passes over the cleaned surface before eggs are laid. Pair formation works best when fish are allowed to choose their own partners from a group raised together, since a forced pairing of mismatched adults can turn one-sided. The marked territorial aggression that accompanies spawning is temporary and centred on the nest, but in a confined tank it is the main behaviour a keeper has to plan around.
Breeding
Spawning is on an open, cleaned hard surface. The pair prepares a flat stone, and the female lays her eggs across it in neat rows — field and aquarium reports put a full clutch at roughly 200 to 500 eggs — after which both parents tend the brood through the familiar division of labour: the female stays close to the eggs, mouthing and fanning them to keep them clean and oxygenated, while the male patrols the perimeter and repels intruders. The eggs are guarded on the rock until they hatch, the wrigglers are then moved to one or more pits dug in the substrate, and once the fry are free-swimming the parents lead and shepherd the school, herding strays back and standing over them against threats. This biparental, open-substrate care — eggs on a stone, larvae in a pit, a guarded free-swimming shoal — is the standard pattern across the cichlasomatine acaras and makes Krobia itanyi one of the more rewarding small Guiana cichlids to breed: parental instincts are strong and reliable, and a settled pair will spawn repeatedly. Newly free-swimming fry are large enough to take baby brine shrimp and powdered foods, and grow on steadily under attentive parents.
In the aquarium
The dolphin cichlid has been a steady, if never flashy, presence in the hobby for decades, valued precisely because it is undemanding. A single pair is comfortably housed in a tank of around 30 US gal or more, but a longer tank pays off: it lets a pair hold a territory at breeding time without cornering tankmates, and it gives a group room to sort out a pairing naturally. Aquascaping should echo the home creek — a soft or fine-gravel substrate the fish can dig in, scattered smooth rocks and driftwood, some shelter, and at least one flat stone that can serve as a spawning slate. The species is tolerant of a wide range of conditions but is at its best in soft to moderately hard, warm water: a temperature of about 75–82 °F and a pH in the soft-acidic-to-neutral band (roughly 5.5–7.5) suit it, with the lower, softer end favouring breeding readiness. It is not especially sensitive, but like all cichlids it rewards stable, clean water and regular partial water changes.
Temperament is the main thing to manage. Away from spawning, Krobia itanyi is comparatively peaceful and mixes well with robust, similarly sized community fish — larger tetras and other characins, peaceful catfish, and calm medium cichlids of the Guiana and wider South American fauna. It will not generally bother anything it cannot swallow. When a pair spawns, however, it claims and defends its patch of the tank vigorously, and small or timid tankmates can be harried; a generously sized, well-structured tank with sightline breaks defuses most of this. The classic pitfall is the mismatched forced pair in too small a tank, where the dominant fish can wear down its partner. Raise a group of six or more young fish together, let a pair form on its own terms, and give them space, and the dolphin cichlid is an easy, long-lived and genuinely engaging cichlid to keep.
Conservation
Krobia itanyi is assessed by the IUCN Red List as Least Concern (assessed 28 December 2020 by D.C. Taphorn and D. Rodríguez-Olarte; published 2022), with a population trend reported as stable. The assessment recognises a range across the Marowijne basin of Suriname and French Guiana and into the coastal drainages of Amapá in northern Brazil, where the species is locally common in its preferred small-creek habitat. It carries no CITES listing and is not evaluated under CMS. The fish is of no fisheries interest as food but is harvested commercially for the ornamental aquarium trade, a use the Red List does not flag as a population-level threat for so widespread and adaptable a species. The broader backdrop is the general pressure on Guiana-Shield freshwaters — deforestation, sedimentation and, in places, alluvial gold-mining with its associated mercury contamination and turbidity — but none of these is documented as a present danger to this particular cichlid, which remains one of the more secure cichlids of the region.