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Greg Steeves,
Cichlid Room Companion
Furu Fanatics

Platytaeniodus sp. "Red Tail Sheller"

作者 , 2006. image
最後更新情形 07-7月-2006



Although the waterways of the Lake Victoria region contain some of the most brilliantly colored cichlid fish on the planet, much confusion often accompanies their nomenclature. Much progress has been made scientifically describing and classifying these species but there is much more work to do. Many undescribed species go by common descriptive names that were usually given by the collector in the field in an attempt to categorize the many new discoveries. In other cases, additional names are given by importers, distributors or hobbyists. This can be very confusing especially when more than one moniker is given to a single species. It would seem that this is the case with the Platytaeniodus sp. “red tail sheller”.

To the best of my knowledge, “red tail sheller” was the name given to a beautiful little molluscivore collected near Hippo Point on the Kenyan shoreline of Lake Victoria. It became an ideal captive species and made its way into aquaria across Europe and North America. Somewhere along the way (and rather recently) a hobbyist in the US decided to rename the species Haplochromis sp. “blue neon”. I’m not exactly certain of why the new name arose (similar cases are usually the attempt by an individual to create the excitement of a new species for financial gain) and all it has succeeded in doing was creating additional unneeded confusion. This species was assigned to the generic “catch all” genus of Haplochromis. The Haplochromis classification has become a scientific holding pattern for the cichlids of the region until further research and information can be gathered to properly classify the undescribed.

In 1956, Greenwood reexamined Boulenger’s 1906 description of Platytaeniodus degeni. Characteristics distinct to this species included a wider and more robust premaxillary as compared to other haplochromine types from the region. The dental pattern is “U” shaped with wide tooth bands at the back of the mandibles. There are between 4 and 7 tooth rows. The “red tail sheller” also processes these traits and superficially, there is no difference in body structure between the degeni and “red tail sheller”. The only visible difference I was able to observe was the intensity of coloration on the “red tail sheller” was more vibrant among dominant males than that of the degeni. Body structure, torso patterning, distribution of color is quite close in both fish. Any discrepancy is certainly no greater than individual variation within a species. Perhaps the most striking similarity is the distinct cranial structure. Both fish are snail shellers in the wild. Platytaeniodus degeni was said to have a wide distribution throughout Lake Victoria before the up serge of Lates niloticus. One cannot help but consider the possibility that the red tail sheller be a locale variant of P. degeni. I’m sure when the time comes for closer classification, this possibility will be examined but in the meantime, and the two fish are considered separate species. It is with certainty that the “red tail sheller” be placed in the same genus as the degeni, Platytaeniodus. Other sources have referred to P. sp. “red tail sheller” as a Ptyochromis. The members of the Ptyochromis genus consist of snail shellers as well. The most obvious difference between the two groups of fish is the dental pattern. Ptyochromis species taper off to a single row of teeth posteriorly whereas the teeth of Platyaeniodus species come to an end bluntly. The jaws of Ptyochromis species protrude evenly unlike Platyaeniodus.

Platytaeniodus sp. “red tail sheller” grows to an adult size of 14cm. There is little dimorphism between the sexes with the female perhaps remaining slightly smaller than the male. The male goes through many color variances. Darker coloration is directly correlated to dominance. The flanks are lined with nine vertical dark bars. There is a slender mid lateral stripe as well as a dorsal stripe following the lateral line. The body is a dark blue, almost black in the most dominant of males, and lighter as the fish in a colony move down the pecking order. The caudal fin is a brilliant crimson red. The anal fin is dark at the base flowing to a red hue at the outer portions. One or two well developed orange ocelli with a clear orbit dot the rear portion of the anal fin. The dorsal fin is blue with red edging growing more pronounced toward the posterior. The pectoral fins are jet black. There is a wide bar beginning at the corner of the mouth and continuing through the eye. There is another black bar running vertically half way up the gill plate. The cranial slope is convex with a pronounced premaxillary hump at eye level. The mouth is turned down with the upper jaw protruding slightly beyond the lower. Female coloration is a tan silver coloration with a pronounced mid lateral horizontal bar. The dorsal and caudal fins have red edging. The base coloration of the anal and caudal fins is translucent with a yellow tinge. The anal fin contains a single primitive egg spot. Females sort a pecking order out amongst themselves as well with the dominant female displaying the most color.

I was fortunate to receive a small group from Rare Dave Schumacher. At that time they were 4cm, colorless with a checkerboard body pattern. I had previous experience maintaining P. degeni and used much of what I had learned setting up the tank for my new P. sp. “red tail sheller”. The colony was placed in a 65 gallon tall tank with similar sized Yssichromis sp. “blue tipped”. A rock formation was constructed at one end with artificial Vallisneria clumped in a group at the other. Mid tank contained open areas. The substrate consisted of coarse white sand. An Aquaclear® 300 creates current and helps maintains water quality. Bi-weekly 20 gallon water changes are carried out. There are no heaters on my tanks and this time of year in south Texas, the water temperature in my fish room sometimes gets close to 90°F. So long as close attention is given to water quality (warmer water is less forgiving) the fish suffer no ill effects. The colony is fed basic flake and small shrimp pellets.

Once the fish matured, it became apparent that I had six males and two females in my group. Males began squabbling for the best real estate in the tank. This “prime location” is an area near a rock pile where a pit can be excavated. Maintaining this pit and defending the area from co specs is a full time job. Other males nearby continuously balk at one another trying to stretch the limits of their territory. This is highly entertaining for the spectator as well as for the ripening females. The males that are not able to secure any primo areas resort to excavating their pits at the corners of a tank. This gives the appearance of a well designed bower. When the male is satisfied with his construction, he intermediately turns his attention to the other sex. Frantic dancing in front of a prospective mate with the objective being to lure the female to his pit for procreation commences. The female will look at the pit briefly. If she shows any indecision, she is quickly driven away by the male. This is all forgotten once she wanders near his pit again. He once again meets her with the frantic “haplochromine shake”. Eventually she finds a excavation to her liking, or perhaps it’s the males dance, but she gives in. Circling ensues with the male displaying his outstretched anal fin against the substrate and the female nuzzling at his ocelli. Once the female has picked up her eggs, she is driven from the male’s territory. She is usually not harassed and can incubate her brood in relative peace. Small brood sizes of 12 larvae are normal. It is sometimes tough to tell if a female is holding because the buccal cavity is not noticeably enlarged. Three tell tale signs of a brooding female is a subtle constant “chewing’ motion, lack of eating (although I have seen incubating females nibble slightly at food), and, when observing from the rear, the gills flare noticeably. The incubation period lasts 18 days at which point the females will release the fry periodically to forage. They retreat back into her mouth at the slightest twist of her head (presumably the signal that danger is near). After two weeks the fry are ignored and left to fend for themselves. I have both separated a holding female to a small tank, and more frequently stripped after two weeks. Both methods have been successful. Rearing the fry has been undemanding. They take readily to crushed flake and Cyclop-eeze®. The fry grow rapidly and have a high survival rate.

It has been noted by others that P. sp. “red tail sheller” is an aggressive fish with its own kind. Perhaps I’ve just been fortunate that my group has coexisted well together. I think a larger tank is needed to successfully house a colony and maybe the lopsided ratio of males to females is actually working in my favor. Perhaps the males are able to spread their aggression in the form of territory defense with one another, deferring the violence that might be directed towards the females in other arrangements.

As the name implies, P. sp. “red tail sheller” should eat snails. I have had Malaysian trumpet snails Melanoides tuberculata inhabit the tanks of both P. degeni and P. sp. “red tail sheller” but have never observed their snail eating behavior. Perhaps this is a case of an unfamiliar snail species or adapting to a more readily available food source (commercial aquarium food). Whatever the case, this incredibly beautiful little cichlid is a fantastic species for the hobbyist to maintain. A little understanding and providing basic requirements is all that is needed to be entertained with years of enjoyment from this, one of the most endearing little cichlid species from Lake Victoria.

Thanks to Kevin Bauman, Dave Schumacher and Nick Andreola for their insightful observations.


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引語:

Steeves, Greg. (7月 07, 2006). "Platytaeniodus sp. "Red Tail Sheller"". Cichlid Room Companion. 檢索 4月 16, 2024, 來自: https://cichlidae.com/section.php?id=142&lang=zh.