Picotee Splitfin

Picotee Splitfin, Zoogoneticus quitzeoensis

The Picotee Splitfin, Zoogoneticus quitzeoensis, whose common Spanish name is picote, is a member of the Splitfin or Goodeidae Family, known collectively as mexclapiques in Mexico. The name quitzeoensis is derived from the lake of the original collection, Lago de Cuitzeo, which was translated to Lake Quitzeo in English. There are two known species in the genus Zoogoneticus, the fish described here and the Tequila Splitfin, Zoogoneticus tequila, now extinct in the wild.

The Picotee Splitfins have overall rectangular bodies that taper anteriorly to a modestly pointed snout and posteriorly to a rectangular caudal peduncle. They vary in color with males being darker olive than females. Both sexes transition to pale yellow ventrally and are mottled with a lateral stripe mid-body that runs from the eye to the caudal base. Young adults have a series of four large spots located ventrally toward the rear. Adults have spots at the base of their caudal fin; in males, these spots fade in color as they age. Males have dark anal, caudal, and dorsal fins that fade in color toward the margins; these fins are dusky in females. Males have a thin red-orange band at the margin of their anal and dorsal fins which is absent in females. Their pectoral and pelvic fins are colorless. Their head has a short snout and a small terminal mouth equipped with conical teeth. They have large eyes set in the mid to upper part of their head. Their dorsal fins have 11 to 13 rays. Their anal and dorsal fins are set well back on the body. Their caudal fin is rounded.

The Picotee Splitfins are found demersal at depths up to 5 feet in clear, turbid, and muddy slow-moving freshwater bodies including lakes, ponds, streams, springs, and outflows over clay, gravel, mud, rocks, sand, and silt substrates that are heavily vegetated. They reach a maximum length of 6.3 cm (2.5 inches) with females being slightly larger than males. They are carnivores feeding on small invertebrates and insect larvae. Reproduction is viviparous and involves internal fertilization followed by a short gestation period. Females give birth every 55 days. They are scientifically interesting because they have two different subspecies based on molecular genetics – one from north of the Río Lerma area and the second from the Lago de Cuitzeo and Lago de Zacapu areas.

In Mexican waters the Picotee Splitfins have a limited distribution and are found in the freshwater systems within the Mexican Plateau in west-central Mexico, such as in the Lago de Cuitzeo, the Lago de Zacapu, and the Río Lerma basins in the state of Michoacán, which are part of the Pacific drainage.

The Picotee Splitfin is most likely confused with the La Luz Splitfin, Zoogoneticus purhepechus (longer dorsal fin with 13 or 14 dorsal rays; found in more westerly locations including the Río Ameca basin and Lago de Camécuaro in Jalisco).

The Picotee Splitfins are used on a limited basis by freshwater aquarists but are unpopular as they require large tanks with dense vegetation and need high maintenance, including frequent water changes and constant water temperatures below 24oC (75oF); they are also known to attack fellow tank mates and to cannibalize juveniles. From a conservation perspective they are currently considered Endangered or Critically Endangered. They have disappeared from several known sites and are now found only in a few small and isolated locations. They suffer from a lack of regular monitoring and historical site-specific population data. The water habitat in some parts of their range has experienced a staggering amount of degradation during the 20th century and they are heavily preyed upon by various birds and recently introduced non-native fish including Black Bass, Guppies, Sunfish, and Tilapia.

Picotee Splitfin, Zoogoneticus quitzeoensis, FemaleFish caught in Lago de Zacapu, Angostura Springs, within the Mexican Plateau in west-central Mexico, Michoacán, February 2017. Length: 6.3 cm (2.5 inches). Catch, photo, and identification courtesy of Ben Cantrell, Peoria, IL.

Picotee Splitfin, Zoogoneticus quitzeoensis, Male. Fish caught in Lago de Zacapu, Angostura Springs, within the Mexican Plateau in west-central Mexico, Michoacán, February 2017. Length: 4.4 cm (1.7 inches). Catch, photo, and identification courtesy of Ben Cantrell, Peoria, IL.