วันพุธที่ 21 มกราคม พ.ศ. 2558

Fish Data : Poll's Tropheus Cichlid

The Poll's Tropheus was described by G.S. Axelrod (1977) and placed in a category of its own due to its unique lyre-tail caudal fin, having only 4 rays on its anal fin, and having an individual place of origin. The Tropheusbecame a big hit when first introduced in Germany in the mid 1970's and then into the United States, and are still very popular today. Many of the imports were identified as T. Moorii varieties, but now it is recognized that these fish represent a number of different species. There are many color morphs of the different Tropheus species, well over 40 varieties of T. Moorii. The Poll's Tropheus has at least three color morphs.

   A colony of 12 or more Poll's Tropheus can make an active display and their personality is a definite plus. The Tropheus have a really interesting social structure that is built upon a colony of consistent tank mates. They are very active and have individual behaviors, from curiously lining up to watch the goings on in the room to their 'dolphin-like' antics when eating. Feeding time can be very 'wet' for their keepers, but make this fish very fun and desirable. In the wild they are very aggressive with conspecifics, but are said to be less aggressive with other fish. In the aquarium their aggression level towards unrelated fish can vary depending on the personalities of the individual fish.

   They are rather expensive fish and they can be afflicted with the occurrence of 'bloat', and there seems to be no explainable rational as to its cause. Initial attempts to keep them often met with difficulty until aquarists became familiar with their rather specific, though uncomplicated needs. This hearty cichlid can be easy to moderate to keep as long as attention is paid to its diet and mandatory water changes are done, and difficult if they are neglected. Provide a sandy substrate, strong lighting to encourage algae growth, and several rock piles along with rocks formed into caves. Having a very aggressive nature, they are best kept in a species specific tank. Do not add a new fish to an already established colony as this will cause an upset and death. They may also be kept in a larger aquarium with some other herbivorous rock dwelling African cichlids. The larger the tank and the more hiding places you have will help with aggression. Truly a rewarding fish for the aquarist who is willing to provide the necessary care.

    The Poll's Tropheus is a moderately deep bodied fish that seems to have a larger head in proportion to its body and the body narrows as it forms the tail. The body of a mature male is a slate gray or solid brown color while the female and juveniles will have light vertical striping. Like the Blue-Eyed Tropheus Tropheus brichardi, its eye is a bright turquoise in a well-maintained aquarium. It is distinguished from the other species in theTropheus genus as it has a deeply forked caudal fin rather than the fan shaped fin found on the others. The caudal fin becomes even more deeply forked with age.

  All cichlids share a common feature that some saltwater fish such as wrasses and parrotfish have and that is a well-developed pharyngeal set of teeth that are in the throat, along with their regular teeth. Cichlids have spiny rays in the back parts of the anal, dorsal, pectoral, and pelvic fins to help discourage predators. The front part of these fins are soft and perfect for precise positions and effortless movements in the water as opposed to fast swimming.

   Cichlids have one nostril on each side while other fish have 2 sets. To sense "smells" in the water, they suck water in and expel the water right back out after being "sampled" for a short or longer time, depending on how much the cichlid needs to "smell" the water. This feature is shared by saltwater damselfish and cichlids are thought to be closely related.

The Poll's Tropheus is an omnivore. In the wild they feed on algae scraped from the rocks along with microorganisms. In the aquarium they need to be fed a spirulina based flake and pellet. If you use pellet, hold it underwater for a few moments before the fish eat it, that may prevent air released from the pellet from getting trapped in the belly. They should have spinach or romaine at least once a day. Only include foods that are high in fiber. Avoid soft or slimy foods as well as Tubifex, brine shrimp, beef heart, and mosquito larvae.

   Feed proteins sparingly and avoid housing them with fish that need protein. Some aquarists say protein may cause bloat though others report no problems with it. Some have fed their fish frozen brine and plankton will no ill effects, while according to one author brine shrimp and insect larvae should be avoided. Stick with the same varieties of food and if you do switch, do it a little at a time, again because this may cause bloat. Rick Borstein, a writer on care of many cichlid fish, suggests HBH Graze and Dainichi Veggie Deluxe brand foods for the Tropheus. The ratios of vegetable matter in these products are good.

   They have a long intestinal tract and should not be over fed, as overfeeding may contribute to bloat. Feed 3 times a day with small pinches of food instead of a large quantity once a day. This will keep the water quality higher over a longer time. All fish benefit from vitamins and supplements added to their foods. (See information about African Bloat in the table below.)

  As the Tropeus cichlids are very aggressive a minimum 4 foot, 90 gallon tank is suggested for an established adult group of 12 or more, with one or two males in the group. Provide a sandy substrate, strong lighting to encourage algae growth, and several rock piles along with rocks formed into caves. They do fine in either freshwater or brackish freshwater but need good water movement for good oxygenation along with very strong and efficient filtration. For freshwater an optional practice is to add 1 heaping teaspoon of salt per 11 gallons of water. This is considered to be a simple and natural remedy for wounds, minor fungal infections and film over the eyes of fish in transit. Be very careful to not add too much salt as this may cause bloat. Using a marine salt (used for salt water fish) will add some trace elements.

   Do water changes regularly, this is very important. Water changes of 15% twice a week or 30% weekly, depending on stocking numbers and removing uneaten food will help prevent disease. The Lake Tanganyika cichlids cannot handle large water changes very well unless the new water chemistry closely matches the water they are in. If a large water change is needed, changing 15% every couple of days should bring water back to normal. This inability to tolerate large water changes is due to Lake Tanganyika being very deep and the water tends to stay stable.

   These fish are susceptible to typical fish ailments, especially if water is stale and of poor quality and has low oxygenation. An ounce of prevention is worth a pound of cure. Water changes, not overfeeding, providing adequate hiding places, and observation along with feeding your fish the proper foods will keep them in optimum health. One common problem is Ich. It can be treated with the elevation of the tank temperature to 86° F (30° C) for 3 days. If that does not cure the Ich, then the fish needs to be treated with copper (remove any water conditioners). Several copper based fish medications are available for Ich. Copper use must be kept within the proper levels, so be sure to follow the manufacturers suggestions. You can also combine increasing the temperature with an Ich medication treatment. A copper test also can be used to keep the proper levels.

  The Poll's Tropheus has been bred in captivity. Get a group of 12 to 20 juveniles for a 90 gallon tank and a harem should form. Do not add new individuals to an existing colony. A large numbers of females is needed for the best success. This keeps the aggression of the males divided and you are less likely to lose females. Females can be hard to bring into breeding condition. The male will always be ready to spawn and are constantly trying to coax the females to spawn whether they are ready or not.

  The dominant male of the group will court a female and they will shimmy and circle one another. The female takes fertilized eggs into her mouth. She will carry them in her mouth, and when release will be healthy, large fry ready to feed. They can be fed crushed flake since they are pretty big when they are born. New moms tend to not be so successful with their first broods, so expect to lose the first sets of fry. The fry are 1/2" (1.27 cm) when they are born, making them easy to feed. With in a week they are already scrapping with each other.

   The adults in the community leave the fry alone if there are plenty of places to hide, but if you have other types of fish in the tank you may choose to remove the fry. They will breed about once a month. Breeding a wild caught specimen with captive bred fish helps to keep the lines healthier.

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