Neochromis (Boulenger 1906), a Genus Review

Neochromis (Boulenger 1906)

The animals making up the genus Neochromis are small cichlids reaching a maximum size of 15 cm. These fish have a curved cranial profile akin to the genus Tropheus from Lake Tanganyika. This “rounded face” is also seen to some degree in the Macropleurodus and Ptyochromis lineages. The coiled intestine is 3-4 times the body length similar to Xystichromis and Enterochromis species. Tooth structure is mostly bicuspid in the outer rows while tricuspid teeth lined the 3-8 inner rows. Teeth are tall with a rounded diameter and gradually depress in height the further back they are implanted within the mouth. Neither jaw protrudes past the other. The mouth is lined bluntly against the cranium and opens to a horizontal rectangular orifice. Neochromis species are rock grazing scrapers that consume algae or the food associated therein.

Past common misconception had been that the scraper types were not as well represented in Lake Victoria as the other great African lakes. Neochromis rufocaudalis (Haplochromis nigricans) had been well known for decades but little else of the assemblage had been documented. In the 1980’s other scraper species began to emerge. Today, only a meager sampling of Neochromis types have been described but other new species are being discovered with regularity. The epilithic algae scrapers (Witte & Van Oijen, 1990) are certain to encompass many new species, variants and complexes. Ole Seehausen has given descriptive field names to 20+ additional species of apparent Neochromis lineage but it is not known at this time if these cichlids are to be classified as distinct species or are representatives of the described assemblages.

fuscus (Regan, 1925)

Neochromis fuscus is one of two known representatives of the genus from Lake Edward Uganda (the other being N. serridens).

gigas (Seehausen and Lippitsch, 1998)

Neochromis gigas is native to the south eastern portion of Lake Victoria in Tanzanian waters. Locales include Makobe Island, Igombe Island and Bwiru Point. There is a population of a N. gigas type found at Bihiru Island but at present it is unknown if this is the fish in question or a closely related undescribed animal (Seehausen, 1996). This is one of the largest species of the genus attaining a length of 15cm and before officially being described, Neochromis gigas was known by the fitting field name of “giant scraper” (gigas=giant; Latin).

Superficially Neochromis gigas resembles Neochromis rufocaudalis in coloration barring and body shape. It is a deep bodied cichlid with a convex cranial profile. Alpha males display dark blue body coloration and 6-7 vertical back bars. There are traces of red in the anal and caudal fins. A small number of ocelli (usually 4) dot the anal fin. Lips are bright blue and the head is wider than other described Neochromis species. Four to seven rows of tricuspid inner teeth line both jaws. Outer rows are bicuspid in structure. The premaxillary is well developed and extends beyond the cranial slope rendering an appearance similar to the Petrochromis sp. of Lake Tanganyika.

Neochromis gigas is found over a rocky substrate slightly inclining close to shore in up to 4m of depth. Subdominant males as well as females form grazing groups scraping plant material and diatoms from the algal masses. In the wild Neochromis gigas is a polygynous mouth brooder, but in the aquarium observations, the male can share in mouth brooding as well as brood care post release (Seehausen, 1998). This biparental behavior is unique amongst the Lake Victoria cichlid fauna.

greenwoodi (Seehausen & Bouton, 1998)

Formerly known as Haplochromis sp. “velvet black”, Neochromis greenwoodi is named in honor of the late British ichthyologist P.H. Greenwood. At 14cm, this is one of the larger Neochromines. Neochromis greenwoodi is found in Mwanza Gulf Lake Victoria at Anchor Island, Mushroom Island, Capri Point, the Gabalema Islands and Igombe Island.

Neochromis greenwoodi occurs in a number of color forms. The traditional coloration for which the descriptive name of “velvet black” was derived is a deep blue-black body with red-orange trim to the caudal fin. The back portion of the dorsal as well as the anal is also trimmed in this manner. Lighter blue coloring in the dorsal and caudal is also common in this species. Females can be typically solid dark grey. Quite often a piebald form exists as well. Beautiful OB males are found at Anchor Island. OB females have orange base body coloration. Five vertical bars line the flanks. There are many color phases throughout Mwanza Gulf.

The cranial profile is straight to slightly convex with a protrusion where the mouth begins (especially in adult males). Teeth in the out rows of both jaws are unicuspid as well as bicuspid. Inner rows number 2-7 and are lined rather symmetrically consisting of unicuspid and tricuspid dentition.

Neochromis greenwoodi is omnivorous showing dietary deviations not only between locales but by season as well (Seehausen, 1996). It is common in the shallow inshore waters.

nigricans (Boulenger, 1906)

Neochromis nigricans is restricted to a species found at Entebbe Uganda. The “nigricans” moniker was once used to describe most of the cichlids now making up the Neochromis rufocaudalis species. It is a smaller representative of the genus reaching 8cm. The primary distinguishing factor separating Neochromis nigricans from others of the genus is the presence of enlarged cephalic pores. Neochromis nigricans also has a narrower head and shorter snout than its cousin. It is, in all probability, a rock grazer incorporating algae and the creatures harbored within to its diet.

omnicaeruleus (Seehausen & Bouton, 1998)

Neochromis omnicaeruleus is the formerly known Haplochromis sp. “blue scraper” from islands in Speke Gulf that include Makobe, Ruti, Gana, Miandere, and Mabibi. It grows to 12cm and is also known as Haplochromis sp. “tricolor fulu”. The cranial slope is pronounced and convex. The outer tooth rows contain a greater number of bicuspid teeth than other Neochromis species. The 3-8 inner rows are tricuspid in structure. The name is derived in Latin; omnis meaning “all” and caeruleus meaning “blue”. This refers to the common male color morph.

Males generally grow larger and are more colorful than females. There are several color forms, however in captivity; the variant most common is the blue-black male with an orange blotched female. Five or six vertical bars streak the flanks. There is a yellow morph as well as an OB male form that is most attractive.

Neochromis omnicaeruleus is a solitary species found at rocky inshore areas. It grazes upon algae encrusted rocks feeding on diatoms and occasionally insect larvae (Bouton, 1997)

Males defend territories against co specs. Females will also defend a small territory at the entrance of a crevice where her free swimming brood inhabits. Gestation is about 14 days. The female will continue to scoop her clutch into her mouth for another three weeks post release.

rufocaudalis (Seehausen & Bouton, 1998)

Neochromis rufocaudalis is the new description of a well known species Haplochromis sp. “nigricans”. This species has an extensive lake wide distribution within Lake Victoria. The distinguishing factor in identification of this species is cycloid scales on the caudal and abdominal portions of the body. In other members of the genus the scales are ctenoid in structure (Seehausen, 1998). Neochromis rufocaudalis shows sexual dimorphism with males to 10.4cm while females max out at 8cm. The name is of Latin in origin; rufo meaning red and caudalis referring to tail (red tailed).

The cranial profile is strongly convex. The mouth is rectangular with jaws that extend to a flat scraping structure. The outer teeth are bicuspid while the 4-7 rows of inner teeth are tricuspid. Females are tan brown with a midlateral broken line horizontally crossing the body. The anal and caudal fins in some locales have a dull yellow hue. Males have dark blue-black flanks with 6-7 straight vertical bars ringing the body. Three horizontal bars cross the forehead and a “s” shaped bar passes from the corner of the mouth, through the eye, over the head and back down the other side of the head. Pelvic fins are jet black while the anal fin is flushed red and particularly vibrant towards the anterior portion. The caudal fin is crimson red. The front 2/3 of the dorsal fin is blue highlighted by the dark fin rays. The posterior section is red. A thin red trim lines the dorsal. The lips are bright blue. The body is torpedo shaped akin to many mbuna from Lake Malawi.

In its natural habitat Neochromis rufocaudalis is found in shallow water near shore over algae encrusted rocks. It is most abundant in depths of 1-2m (Seehausen, 1998). It is common to see this species grazing in shoals of individuals, both subdominant males and females of similar size. Females are maternal mouth brooders holding a clutch for up to 21 days and exhibiting further care for another 21 days before the fry are ignored.

Aquarium notes:

Dominant males will stake out a territory, usually in a rock cave or crevice. When not chasing other fish, the male Neochromis rufocaudalis spends his time showing off with a series of "shimmies" to prospective females. It is a beautiful sight to see a large group of these fish grazing an algae covered rock. Reflections cast on their body glitter and gleam in the light.

To keep these undemanding fish in top condition, it is helpful to feed a spirulina based flake in small amounts frequently. This would be a great fish for those hobbyists who feel their animals are always hungry and have the need to sprinkle food to them every time they walk by the tank. Neochromis rufocaudalis are not shy fish and will learn to recognize their feeder on sight. They will remain mostly in the open under captive settings, but caves and secluded places, as well as artificial plants placed throughout the tank will aid in overcoming any timidness. Under a gro-lux lighting scheme, dominate males sparkle and stand out very nicely.

When keeping a group of any type of Victorian cichlid, the bigger the tank, the better. This is a moderately aggressive furu and should be kept in large groups to disperse aggression. I would suggest an aquarium of no less than 55 gallons for a group of twelve Neochromis rufocaudalis. It is not advisable to mix any Lake Victoria rock cichlid species together in a tank due to the possibility of interbreeding; however, one may find it necessary from time to time. Neochromis rufocaudalis might be an exception to this rule. The rounded, tropheus-like head shape allow for easy distinction from most other cichlids from this region. I have had our group housed with many other Lake Victoria cichlids and there were no damaging inter-species conflicts. Males and females of each species are readily able to identify their own and any prelude to breeding activity is kept within same species. When mixing Lake Victoria species, use fish of differing body shape and coloration to avoid possible hybridization.

Neochromis rufocaudalis is a peaceful community fish and mixes well with any of the more peaceful Malawi mbuna. Like so many Lake Victoria rock cichlids Neochromis rufocaudalis it is not a common fish in the hobby.

serridens (Regan, 1925)

Neochromis serridens is native to Lake Edward and grows to 8.0cm.

simotes (Boulenger, 1911)

The description of Neochromis simotes is based on three specimens in a 1911 collection in the British Museum of Natural History. The collection point is listed as Kakindu on the Victorian Nile Uganda. The largest individual is 8.6cm with the typical convex cranial slope distinctive to this genus. Equally bicuspid teeth line the outer rows. The 6-7 rows of inner teeth are of tricuspid structure.

sp. “madonna”

Hailing from Lake Kyoga in Uganda is the beautiful Neochromis sp. "madonna". Like most cichlids from the Neochromis genus of Lake Victoria, Neochromis sp. "madonna" sports a rounded snout. This feature is also found in the Tropheus genus of Lake Tanganyika. Like its cousins, Neochromis sp. "madonna" is an epileptic algae grazer. Les Kaufman dubbed this new species "madonna" in the field based on coloration. Reminded of the blonde hair and black roots of the famous singer, Kaufman correlated this to the dorsal coloration of this cichlid. There are inter-specific coloration variants within this species. Generally speaking, the body has a copper colored sheen. The bottom portion of the dorsal fin is black matching the coloration of the pectoral fins. One distinguishing characteristic of this species is bright blue lips in dominant males. This feature is quite striking. The anal fin is translucent with a red hue. Between two and four well defined yellow egg shaped ocelli adorn the anal fin as well. The coloration of the caudal and dorsal fins range from copper toned to classic Victorian red. Vertical barring is often most present in males while females show faded vertical barring with a broken line running laterally across the body.

Neochromis sp. “madonna” is extremely prolific. The males