Translations:Adventist Youth Honors Answer Book/Nature/Fishes/16/en
They are well-documented cleaner fish, setting up stations where often much larger fish (sometimes even fish who would normally eat the gobies) come to have the gobies eat their small external parasites. This is an excellent example of symbiosis – the cleaned fish are healthier and the gobies have not only an excellent food source but also relative protection from potential predators. | range = Neon gobies are native to the tropical reefs of the Gulf of Mexico, from Texas to Belize, where they live primarily in the rocks. | reproduction = If kept in pristine conditions and fed well neon gobies will readily spawn in home aquaria. A species or breeding tank is required, as the fry are small and will be eaten by most other fish. The gobies are sexually dimorphic, but the difference is not easy to ascertain so they are normally kept in large groups to ensure a balance of sexes. They will lay their eggs on any hard surface along the bottom, and the fry, which feed on small rotifers or other microscopic organisms, are fully developed within a month. The average lifespan for a neon goby is approximately a year to a year and a half. }}
Green Swordtail
Xiphophorus hellerii
Green Swordtail (Xiphophorus hellerii)
Where found: It is native to an area of North and Central America stretching from Veracruz, Mexico, to northwestern Honduras.
Description: The male green swordtail grows to a maximum overall length of 14cm
and the female to 16 cm. The name "swordtail" is commonly but mistakenly believed to be derived form the elongated lower lobe of the male's caudal fin (tailfin), but is actually derived from the sword shaped anal fin of the male. Sexual dimorphism is moderate, with the female being larger than the male but lacking the "sword". The wild form is olive green in color, with a red or brown lateral stripe and speckles on the dorsal and, sometimes, caudal fins. The male's "sword" is yellow, edged in black below. Captive breeding has produced many color varieties, including black, red, and many patterns thereof, for the aquarium hobby.
Reproduction: The males' elongated caudal fins have been found to significantly affect their chances at mating. The presence of a well-endowed male spurs the maturity of females while it inhibits the maturity of juvenile males in the vicinity as the well-endowed male.
