Order Cyprinodontiformes
Suborder Cyprinodontoidei
Family Goodeidae
Subfamily Goodeinae
Genus Allodontichthys
— Allodontichthys hubbsi [Miller & Uyeno, 1980]. (Whitepatched Splitfin). Mexico, Lerma River. 6 cm. Beige-silver coloration with 8-14 dark vertical bars on the posterior part of the body. Due to the aggressive nature of these fish, it is important to use large aquariums equipped with plenty of hiding places made of plants, rocks, and roots.
Fish occupy territories which they defend against other males so vigorously that the winner will sometimes kill the opponent. They swim near the bottom and lead a solitary lifestyle among rocks, stones, and roots. They require clean, hard water with a pH of less than 7. In winter, as well as at night, the temperature should be kept relatively low. Feed with flakes, frozen, and live foods, as well as supplemental vegetable matter. dH 5-20°; T 18-23°C.
— Allodontichthys polylepis [Rauchenberger, 1988]. (Finescale Splitfin). Mexico, Ameca River. 6 cm. They swim near the bottom. A spacious aquarium with plenty of hiding places, boulders, driftwood, dense vegetation, and floating plants is required. The fish are aggressive, and males defend their territory against any intruder. In winter and at night, the temperature should be kept relatively low. Breeding is quite difficult, and only specialists can achieve success. A single brood consists of only a few fry. pH 7.0-8.0; dH 5-20°; T 20-24°C.
— Allodontichthys tamazulae [Turner, 1946]. (Tuxpan Splitfin). Mexico, Tamazula River. 5-8 cm. Olive coloration with blue scales and a coffee-blue stripe extending from the gill covers to the caudal fin, which is less pronounced in older fish. Some fish (mainly males) have a large dark spot on the upper body. Their aggressiveness is not as intense as that of A. hubbsi, nevertheless, appropriately sized aquariums are necessary.
A spacious aquarium with plenty of hiding places, boulders, driftwood, dense vegetation, and floating plants is required. Fish are aggressive and males defend their territory. They swim near the bottom, occupying specific territories. The water must be hard with a pH of less than 7, and water changes should be frequent. Feed with flakes, frozen, and live foods, as well as supplemental vegetable matter; additionally, algae should not be removed from the aquarium as it serves as an extra food source for the fish. pH 7; T 20-24°C.
— Allodontichthys zonistius [Hubbs, 1932]. Synonym: Alloophorus, Zoogoneticus zonistius. (Bandfin Splitfin). Mexico. 5 cm. Silver-yellow coloration with a reddish tint, greenish scales, and a black stripe along the body. The caudal fin is yellow, while the other fins are dark. Their aggressiveness is not as intense as that of A. hubbsi, nevertheless, appropriately sized aquariums are necessary. Aquarium with planted thickets. Swim near the bottom. pH 7.0-8.0; dH 5-20°; T 21-25°C.
Xenotaenia resolanae, Zoogoneticus quitzeoensis, Zoogoneticus tequila. 
