An adult male O. lithobates in nearly full breeding color in an aquarium; note the absence of eggspots. Photo © by M.K. Oliver, Ph.D.

The same O. lithobates, to show the sulfur-yellow blaze on the forehead. Photo © by M.K. Oliver, Ph.D.

 

Otopharynx lithobates Oliver, 1989: Holotype, a male 86.5 mm SL, BMNH 1974.7.5:1, from north shore Thumbi Island West. Collected 24 May 1971 by Assan Mbaye.

Otopharynx lithobates Oliver, 1989

by Michael K. Oliver, Ph.D.

In the aquarium hobby, Otopharynx lithobates is one of the most popular "Haps" or non-Mbuna cichlid species from Lake Malawi. And with good reason! It is readily available, highly attractive, easily maintained, and relatively nonbelligerent, and thus one of the best choices for beginners with Malawi cichlids. It has sometimes been sold under the misleading names "red top Aristochromis" and "Aristochromis lombardoi," although it is distantly related to the only true Aristochromis species, Aristochromis christyi, an oblique-striped predator.

O. lithobates is one of the commonest of the few species of "haps" found over rocky shores; I therefore gave it the name lithobates which means "haunter of the stones." (A word about pronunciation: The name has 4 syllables — "lith-o-bay-tees" is how I pronounce it in the American system, or more like "lith-o-bah-tays" in Europe. Please note that this name is not a plural! It is an amateurish mistake to refer to one individual as "a lithobate"; it is "a lithobates," thank you very much.)

The live holotype of Otopharynx walteri, a male of 99 mm SL (BMNH 1990.4.9: 28), from Nakantenga Island in the Maleri Islands. Photo by Ad Konings, from the original description, Konings (1990); reproduced by permission of T.F.H. Publications, Inc.

I first collected several individuals of this elegantly shaped species in 1968 with David Eccles on my very first trip to Lake Malawi, and it soon became evident that it was undescribed. It is one of the "three-spot" haps, which are now classified in several different genera. It belongs to the minority of "three-spot" taxa in which the most forwardly placed of the large spots (the suprapectoral spot) is placed entirely below the upper part of the lateral line. The combination of a rather elongate body, large eyes, short jaws, and lack of eggspots in adult males further help to identify O. lithobates.

Fully colored adult male O. lithobates photo- graphed underwater at Monkey Bay, Malawi. From Plate 12i of Ribbink et al., 1983 (where it was called "Cyrtocara red dorsal"); repro- duced by permission of the Zoological Society of Southern Africa.

The geographic distribution of O. lithobates is apparently restricted to the southern end of the lake; indeed, Konings (2001a) states that all of its populations are found within the boundaries of Lake Malawi National Park. (I collected one specimen of something very much like O. lithobates at Nkhata Bay, but it is a small specimen and may belong to another species.) There is geographic variation in the color of the dorsal fin and frontal "blaze," with these areas being white in breeding males at Mumbo Island and the Maleri Islands, orange-red in those from Domwe Island, and sulfur yellow in those found at Zimbawe Rock, about 2 km west of the northern tip of Domwe. Konings (2001a) pictures a male at Chinyamwezi Island with both white and sulfur yellow in the dorsal fin and an indistinct blaze.

The population of O. lithobates at the Maleri Islands was named by Konings (1990) as a distinct species, O. walteri. Konings initially believed that this population differed significantly in several respects from those of O. lithobates, which I had based on specimens from Thumbi Island West (the holotype and paratypes) and Monkey Bay. Konings stated that his new O. walteri "...shows a close resemblance to O. lithobates, from which it differs by the noticeably shallower head" (not to my eyes!); by a longer snout (oddly given in relation to body depth instead of head length, which is the standard comparator for head measurements); and in supposedly having "slightly

A male Otopharynx lithobates photographed underwater at Nakantenga Island by Ad Konings, and originally identified by him as O. walteri. A special "Thank you!" to Ad for providing this photo and permitting its use here.

thicker lips, smaller pharyngeal teeth, and more widely spaced teeth in specimens over 80 mm SL." O. walteri was further supposed to differ from O. lithobates in feeding behavior (stalking small Mbuna and eating small invertebrates taken from rock surfaces, versus feeding on particles, especially fish feces, in O. lithobates); and habitat preference (supposedly a predilection for depths greater than 15 meters / 49 feet, versus "found in much shallower regions of the biotope" in O. lithobates). However, in my unpublished dissertation (Oliver, 1984), I had documented the occurrence of O. lithobates "...from near the surface to at least 20 m" (66 feet). I also reported observing this species commonly feeding on zooplankton by picking individual plankters from the water column, and noted that stomach contents "...consisted almost entirely of planktonic crustaceans, chiefly whole animals. Diaptomid copepods predominated, but the cladoceran Diaphanosoma excisum was present in 3 stomachs" (Oliver, 1984). Thus, invertebrate feeding by O. lithobates was clearly documented. More recently, in any event, Cleaver, Konings, & Stauffer (2009)

An adult female O. lithobates in an aquarium; photo © by M.K. Oliver, Ph.D.

have synonymized O. walteri with O. lithobates based on a more-detailed analysis of morphometrics (proportional measurements), which showed complete overlap between the two named forms. So, the two nominal species are now acknowledged to be one and the same, and O. lithobates is their valid name, since it was published first and so has priority.

As I already noted above, O. lithobates is a very satisfactory and relatively easily maintained Malawi "hap" species. A male and two or three females will thrive in a community Lake Malawi tank with other smallish and fairly peaceable species, such as Iodotropheus sprengerae and Labidochromis caeruleus. Their aquarium need not be large; one of 25-40 gallons (95-150 liters) is adequate. Some rockwork caves or other hiding places are appreciated, and a large flat-topped rock may be used as a spawning site. As always, it is important to provide frequent partial water changes in order to maintain water quality and avoid the build-up of excretory products; replacing, say, 20% of the water with dechlorinated fresh water of the same temperature every 7-10 days accomplishes wonders for the health of all Malawi cichlids.

O. lithobates will take a good flake or small pellet food, as well as occasional frozen brine shrimp, mosquito larvae, and the like; and will reach breeding condition on these foods. Females become mature at quite a small size, around 5 cm (2"). My video documenting some spawning behavior is here. An extensive article by Scott Schwerdtfeger on breeding O. lithobates is available at Cichlid Room Companion.

 

 

Last Update: 31 December 2009 Web Author: M. K. Oliver, Ph.D. Copyright © 1997-2021 by M. K. Oliver, Ph.D. - ALL RIGHTS RESERVED