Taxonomy & naming
The fish was described by the Mexican ichthyologist Juan Jacobo Schmitter-Soto in 2007, in his systematic revision of the genus Archocentrus in Zootaxa (1603:1-78), the same paper that erected the genus Rocio for the Jack Dempsey and its relatives and described several new forms. The epithet ocotal is taken directly from the type locality, Laguna Ocotal, a highland water body in the Lacantún–Usumacinta drainage of Chiapas, Mexico, to which the species appears to be endemic. Rocio belongs to the Middle American heroine cichlids and is allied to the firemouths (Thorichthys); it comprises the widespread octofasciata (Jack Dempsey), the Yucatán form gemmata, the Izabal-basin endemic spinosissima, and ocotal. The validity of ocotal is the open question. The Catalog of Fishes (Fricke, Eschmeyer & Van der Laan) lists it as valid Rocio ocotal Schmitter-Soto 2007 on the strength of the original diagnosis, but the Cichlid Room Companion notes that it is most likely a junior synonym of Rocio octofasciata — a highland, yellowish-toned population of that variable and far-ranging species rather than a separate lineage. It was distinguished from octofasciata chiefly by its yellowish hue and details of body proportion and squamation; no molecular study has yet tested whether the Laguna Ocotal population is genetically distinct. Mendoza-Carranza and colleagues' identification key to the cichlids of Chiapas (2022) recognizes ocotal and notes it as the only cichlid endemic to the state.
Morphology
Rocio ocotal is a small heroine cichlid of the Jack Dempsey mould — a modest, oval, laterally compressed body in the same size class as its congeners, well under 8 in. The ground colour is the feature emphasized in its description: a warmer, more yellowish or golden cast than the typically dark, blue-spangled octofasciata, a hue attributed to the highland Chiapas population. Over this ground runs the iridescent spangling characteristic of Rocio — rows of small, light blue-green to turquoise flecks scattered across the flanks, head and fins — together with a pattern of dark vertical bars and flank blotches that intensify with mood and breeding condition. As in the rest of the genus, the markings of the cheek, flank and caudal peduncle carry the diagnostic detail. Sexual dimorphism follows the genus pattern: mature males grow somewhat larger, with longer, more pointed dorsal- and anal-fin tips and often more extensive spangling, while ripe females are rounder-bodied. Because ocotal is known from a single lake and has scarcely been studied beyond Schmitter-Soto's revision, fine meristic detail beyond the original diagnosis is limited, and the colour and proportional characters that separate it from octofasciata are subtle — the heart of the doubt over its rank.
Habitat
The species is apparently endemic to Laguna Ocotal, a comparatively isolated highland lake in the rainforest of eastern Chiapas, Mexico, part of the Lacantún–Usumacinta drainage on the Atlantic slope. This is an unusual habitat for the genus: a clear, standing highland water body rather than the warm lowland rivers, lagoons and floodplains where octofasciata and its relatives typically live, and that isolation is the basis for the population's distinctness — or, on the synonymy view, the source of the local colour form. The lake sits in karst and forested terrain; its water is warm-temperate to warm (somewhat cooler than the lowland habitats of octofasciata given the elevation), generally clear, and neutral-to-alkaline with hardness reflecting the limestone of the region. Like the rest of Rocio, ocotal is a littoral fish of the shallows and margins, associating with submerged structure, leaf litter and aquatic vegetation rather than open water. Its confinement to a single small lake is exactly what makes both its taxonomy and its conservation status sensitive: a genuinely endemic species in one lake is a very different proposition from a colour variant of a continent-spanning species.
Feeding
No dedicated diet study exists for Rocio ocotal, but its feeding ecology can be read from its genus. Rocio octofasciata, the well-studied type, is an opportunistic carnivore-leaning omnivore that takes small fish, aquatic and terrestrial insects and their larvae, crustaceans, worms, molluscs and some plant and detrital matter, hunting from cover among littoral structure. A small highland-lake Rocio such as ocotal would be expected to work the margins, leaf litter and submerged vegetation for insect larvae, microcrustaceans, worms and small invertebrates, taking small fish and fallen terrestrial insects when available. The heroine jaw and pharyngeal apparatus handle a mixed diet that includes hard-shelled prey. Trophically the genus sits in the mid-range of the food web as a flexible, ambush-and-glean secondary consumer — a generalism well suited to the patchy resources of an isolated lake.
Mating
Reproductive behaviour has not been documented specifically for Rocio ocotal, but the genus Rocio is uniformly biparental and territorial when breeding, and there is no reason to expect ocotal differs. As in the well-studied octofasciata, a male and female form a monogamous bond, select and clean a spawning surface in the littoral zone, and defend a territory around it together, becoming markedly aggressive toward intruders during courtship and brood care. Courtship is the standard heroine repertoire of lateral displays, fin-spreading, jaw-locking and cooperative substrate-cleaning, with the female taking on heightened breeding coloration as she ripens. In a highland lake, breeding would track the warm season and the stable shallow-water conditions of the lake margins, where a pair can hold a defensible territory among structure.
Breeding
By extension from the genus, Rocio ocotal is an open biparental substrate spawner. The adhesive eggs are laid in rows on a cleaned hard surface — a flat stone, root, submerged log or firm leaf — and tended by both parents, the female fanning and directly caring for the eggs while the male patrols the perimeter. After hatching, the wrigglers are moved to one or more pits, and once free-swimming the fry are herded and guarded as a school by both parents for several weeks. Clutch size has not been published for ocotal; octofasciata, a fish of similar size, lays clutches of several hundred eggs, and ocotal would be expected to produce comparable broods. The extended biparental care typical of Rocio protects eggs, larvae and free-swimming fry alike, and pairs can spawn repeatedly through the warm season when in condition. No specialised nesting behaviour beyond conventional substrate-spawning is documented for the genus.
In the aquarium
Rocio ocotal is essentially unavailable in the aquarium hobby as a distinct fish — its single small-lake range means it is rarely if ever collected for the trade, and the spangled, golden 'Ocotal' fish that occasionally circulate among Central American cichlid specialists are kept much like a colour form of the Jack Dempsey. Husbandry therefore follows the well-established template for Rocio octofasciata, a hardy and popular aquarium fish. A pair wants a tank on the order of 40–55 US gal or more with an open sandy bottom, rock, wood and structure for cover and territory boundaries, and warm, neutral-to-alkaline, moderately hard water (pH roughly 7-8, temperature around 75–82 °F; ocotal's highland origin means it tolerates the cooler end of that range comfortably). The genus is moderately aggressive and becomes genuinely territorial when spawning, so tankmates should be robust and the tank large enough to give a pair its space. Feeding is straightforward — they accept quality pellets, frozen and live invertebrates and small meaty foods readily. A keeper should understand that ocotal is, at best, a poorly-resolved highland endemic and very possibly just a yellowish population of the Jack Dempsey, and treat it accordingly rather than as a securely distinct species.
Conservation
Rocio ocotal has not been assessed by the IUCN Red List, which leaves a real gap given its apparent status as a single-lake endemic. If it is a valid species confined to Laguna Ocotal, it is among the most range-restricted cichlids in Mexico and would warrant serious conservation attention: a fish in one small highland lake is acutely exposed to any local disturbance — deforestation in the surrounding rainforest, changes in water level or quality, and above all the introduction of non-native fishes, which has devastated isolated cichlid populations across Mesoamerica. The Chiapas cichlid review by Mendoza-Carranza and colleagues (2022) flags exactly this, noting ocotal as the state's only endemic cichlid. If, on the other hand, it is merely a colour form of the abundant and adaptable Rocio octofasciata — as the synonymy view holds — then the lineage as a whole is in no danger. The honest statement is that the taxon is both unassessed and taxonomically unresolved, and that resolving its status is itself a conservation priority: it determines whether Laguna Ocotal holds a unique endemic species or a local variant of a widespread one.