Taxonomy & naming
Paretroplus maculatus was described in 1966 by the French fisheries biologist André Kiener and his colleague Marc Maugé, in their monograph on the endemic Cichlidae of Madagascar (Mémoires du Muséum national d'Histoire naturelle, Série A, Zoologie, vol. 40). The description rests on two syntypes catalogued as MNHN 1965-0315, collected at Ambato-Boemy (Ambato-Boeni) in the Betsiboka river basin; the type locality is discussed in detail by John Sparks in his 2008 revision. The genus Paretroplus was erected far earlier, by Pieter Bleeker in 1868, and the name is transparent: para- ('beside, near') prefixed to Etroplus, signalling a close but distinct relative of the Indian–Sri Lankan genus. Paretroplus is one of three genera in the subfamily Etroplinae, the others being Etroplus and Pseudetroplus of southern Asia; this trans-oceanic distribution is a classic Gondwanan relict pattern, the two lineages having been separated when Madagascar and the Indian plate drifted apart. Sparks's 2008 monograph (Bulletin of the American Museum of Natural History 314) provided a phylogeny of the subfamily and a full taxonomic revision of Paretroplus, placing maculatus within the deep-bodied clade of the genus alongside species such as Paretroplus menarambo, Paretroplus dambabe and Paretroplus petiti. The species epithet maculatus is Latin for 'spotted', referring — per the original authors and confirmed by the ETYFish Project — to the black humeral spot, which enlarges as the fish ages. Konings identifies the pinstripe damba, Paretroplus menarambo, as maculatus's closest relative — a pairing that matters for conservation as much as for classification, since Konings' own account describes menarambo as having been reported extinct in its native habitat, underscoring how precarious this branch of the genus has become (menarambo's status has since been the subject of further field surveys, but the closeness of the two species is the reason keepers are warned not to house them together — see In the aquarium).
Morphology
Paretroplus maculatus is a deep, laterally compressed, disc-shaped cichlid built along the lines of its deep-bodied congeners. FishBase and Sparks's revision give a maximum of 6 in standard length for examined specimens, but well-grown aquarium fish are reported to reach roughly 12 in total length, considerably larger than the museum material would suggest. The fin counts run to 15–18 dorsal spines and 16–20 dorsal soft rays, with 8–10 anal spines and 13–16 anal soft rays. The single diagnostic feature that separates it from every congener is its namesake: a large, essentially square-to-rounded, solid black patch sitting above and slightly behind the base of the pectoral fin, generally not extending above the upper branch of the lateral line. The ground colour is a warm gold-green that, examined closely, resolves into alternating faint vertical lines of gold and green down the flank. The emarginate (shallowly forked) tail and the rear of the dorsal fin carry red edging, and the anal and pelvic fins are margined in black; a dark line crosses the forehead between the eyes. In breeding dress the whole body pales, faint dark bars surface on the flanks, the chin and underside blacken, and the forehead line and a smudge at the caudal base intensify. Juveniles are a plain pale gold and — unlike the closely related pinstripe damba, Paretroplus menarambo — do not show the rows of dark dots, the shoulder spot instead being the first adult marking to appear. Sexual dimorphism is weak and unreliable; mature pairs are not obviously distinguished by size, and ripe females are best told by their fuller body.
Habitat
The species is endemic to northwestern Madagascar, restricted to the lower reaches of the Betsiboka and Ikopa river drainages (it was also recorded historically from the adjacent Mahajamba basin). Its characteristic habitat is turbid, shallow floodplain lakes, together with the small rivers that connect them. The documented range runs from Lac Ravelobe and surrounding waters near the Ampijoroa Forestry Station — within Ankarafantsika National Park, southeast of Mahajanga — southward through the lakes around Ambato-Boeni and Maevatanana, and a further lake near the town of Tsaramandroso where collectors have reported catching numerous large individuals, to Lake Andimaka near Mahazoma, the southernmost known locality. These are warm, mineral-rich lowland waters: in keeping with the floodplain-lake environment of the deep-bodied dambas, the species does best in hard, alkaline, near-neutral-to-basic water rather than the soft acidic conditions typical of Amazonian or Southeast-Asian blackwater fish. Published in-situ chemistry for the specific lakes is sparse, but the genus as a whole inhabits the calcareous, seasonally flooded lowlands of western Madagascar, and aquarists keep the species at roughly 75–82 °F with a pH at or above neutral (about 7.0–8.5). Field collecting at Lake Ampijoroa found both this species and Paretroplus kieneri in water less than 7 ft deep over a sandy bottom, consistently associated with submerged debris such as branches and other plant litter — so the fish occupy a narrow depth band, typically the upper couple of metres, feeding at mid-water and along the bottom over sand and submerged wood.
Feeding
Paretroplus maculatus is a benthic-feeding invertivore that works the substrate in a distinctive way: rather than a simple mouthful-and-spit sift, it sweeps its head from side to side over the bottom, digging a series of small pits as it searches for food — a technique reported specifically for maculatus, menarambo and kieneri among the dambas. FishBase places it at a trophic level near 2.9. Like its congeners it is equipped with unicuspid (single-pointed) teeth well suited to crushing and gripping hard-shelled prey: in the wild the dambas feed largely on crustaceans and molluscs, and in the aquarium the species is a notorious snail-eater, capable of clearing a tank of pond snails in a matter of minutes. It readily takes a wide range of foods and is not a specialist of any single item. In its native floodplain lakes it functions as a mid-level consumer of the benthic invertebrate fauna, a role that — combined with its former abundance — once made it an important and sought-after food fish for local communities.
Mating
Like the other deep-bodied dambas, Paretroplus maculatus is a biparental species that forms genuine pair bonds, and it is best kept in groups so that pairs can form by mutual choice. Aquarist observation, principally by the European keepers who have maintained the species, shows that the two members of a pair are not reliably distinguishable by size — neither the largest nor the smallest fish in a group is necessarily part of the first pair to form. A forming pair pales into breeding colour, stays side by side through the day, and together clears and defends a chosen spawning site, breaking off only to drive away rival conspecifics. Courtship follows the stereotyped damba ritual: the displaying fish lowers its head and vibrates its body, and the partner answers in kind. As with most Paretroplus, the species is quarrelsome toward its own kind, and an isolated individual in a small group is liable to be harried to death — a serious risk given how few fish exist. Keepers who begin with too few specimens have repeatedly ended up with a single survivor, which is why a shoal of at least half a dozen, in a large tank, is the standard recommendation.
Breeding
Paretroplus maculatus is a biparental substrate spawner. Unusually for the genus, and distinguishing it from its close relative Paretroplus menarambo (which lays on horizontal surfaces), it prefers to deposit its eggs on a vertical or steeply angled surface — the side of a piece of bogwood, or a vertical rock face — a preference reported independently by more than one breeder. The pinkish eggs are laid in the typical cichlid fashion, the pair taking turns over the chosen surface, after which both parents guard and fan the clutch and hold other fish at a distance. Documented captive clutches have been modest, on the order of a few dozen to perhaps a couple of hundred eggs, and the species has proven difficult to bring through to free-swimming fry: keepers have repeatedly recorded clutches vanishing overnight, sometimes traced to one of the parents eating the eggs rather than to tankmates. Where parental care does proceed, the female has been reported to tend eggs and fry for the first two to three weeks. Successful captive spawnings have nonetheless been achieved on both sides of the Atlantic, and — given that the species is now nearly gone in the wild — these aquarium breedings are central to its survival. The species has also reproduced successfully outside the traditional hobby tank: conservation-aquaculture ponds at Lake Ampijoroa produced good numbers of both P. maculatus and P. kieneri, suggesting the extra space and more natural substrate of a pond setting may suit the species better than a standard aquarium. Even so, the breeding biology of P. maculatus was, for years, described by aquarists as considerably less well documented than that of easier-to-breed relatives — one long-term keeper reported repeatedly observing a female's ovipositor extended and ready, without ever seeing the pair follow through to a successful spawn. Reliable triggers and a fully proven rearing protocol are still not as well established as for the more tractable dambas such as Paretroplus damii.
In the aquarium
Paretroplus maculatus is a specialist's fish rather than a beginner's, kept mainly within Madagascar-cichlid and conservation circles. It is large, long-lived and quarrelsome toward its own kind, so the foundation of success is a big tank and a group: experienced keepers advise a shoal of at least six fish in an aquarium of around 130 US gal or more for adults, so that aggression is diffused across many individuals and no single fish is singled out and killed. Starting with four or fewer fish is a documented route to ending up with one.
Water management matters more than for most cichlids. The dambas come from warm, hard, alkaline floodplain lakes and are sensitive to accumulated waste, so the species wants well-filtered, frequently changed water held above neutral pH — roughly pH 7.0–8.5 — and warm, in the region of 77–82 °F (above about 75 °F). Generous, regular water changes are part of the standard regime; long-term keepers report weekly changes of a quarter or more on mature, heavily filtered systems. A substrate of inert sand suits the species' habit of sifting the bottom, with bogwood, rounded stones and open swimming corridors that lengthen sightlines and let subordinate fish keep their distance.
Diet is straightforward: a varied menu of quality dried foods plus frozen brine shrimp, bloodworm, mysis and daphnia is taken eagerly, and the unicuspid dentition makes the fish an efficient snail controller. Compatibility within the genus needs a specific caveat: it can generally be housed with Paretroplus kieneri, P. petiti or P. dami without hybridising, though even those pairings carry a small, occasionally reported risk — but it should not be kept with its closest relative, P. menarambo, since the two are close enough that hybridisation is a real concern rather than a remote one. The genus as a whole, this species included, is reported to be quite adaptable to a range of water parameters once past that core requirement, which helps in mixed Malagasy-cichlid setups. The critical danger, as with the rest of the genus, is always intraspecific rather than interspecific: putting together just two adults, rather than a full group, is close to a guarantee that one will kill the other, and rival adults or pairs defending a spawn can turn lethal even in a proper shoal. Larger robust catfish and other sizeable, non-fin-nipping companions can share the tank. The honest assessment is that this is a demanding, slow-maturing fish whose chief value to the hobby is conservation; anyone keeping it should aim to breed it and pass fish on to other serious keepers.
Conservation
The IUCN Red List assesses Paretroplus maculatus as Critically Endangered (assessed 15 May 2016 by J.S. Sparks; criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)), with a decreasing population. Collections by Sparks and colleagues over many years document a severe decline throughout the species' range, and recent surveys have repeatedly failed to find the fish in former localities. The drivers are heavy fishing pressure — it was a highly prized food fish — together with widespread habitat degradation and the introduction of exotic species, most damagingly the Asian snakehead (Channa), a voracious predator. Introduced tilapiine cichlids, stocked decades ago to boost food-fish production, compound the problem by sheer numbers rather than predation: field collecting outside protected areas has found tilapia outnumbering native Malagasy cichlids in seine hauls by as much as fifty to one, effectively displacing species like P. maculatus from unprotected waters even where the habitat itself is intact. Lac Ravelobe, inside Ankarafantsika National Park, once offered the species some protection, but on the most recent survey (2011) no specimens were found there; the lake had become heavily degraded and choked with invasive water hyacinth (Eichhornia crassipes), and existing park regulations are not adequately enforced. Restoration of that habitat — clearing the hyacinth and rebuilding the lake's ecology — is among the actions the assessment flags as needed. Paretroplus as a whole is one of the most threatened cichlid genera on Earth, and for the spotted damba the realistic safety net at present is the network of captive-breeding programmes in European and North American aquaria, which keep the species alive while its wild floodplain lakes remain in crisis. It carries no CITES listing.