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Morfometría comparada del aparato mandibular en especies de Chirostoma (Atheriniformes: Atherinopsidae) del Lago de Pátzcuaro, Michoacán, México

2005; Universidad Autónoma Metropolitana; Volume: 15; Issue: 2 Linguagem: Inglês

2448-7333

Miriam Soria‐Barreto, Joel Paulo-Maya,

Fish Biology and Ecology Studies

The genus Chirostoma is a group of fishes endemic to the Mesa Central of Mexico, whose diversification is explained both by processes of allopatric speciation in lotic environments, and by intralacustrine diversification through sympatric speciation. Trying to corroborate the second hypothesis for species of Chirostoma from Lake Patzcuaro, we evaluated morphometric differences of 11 bones in the mandibular region of C. attenuatum, C. grandocule, C. estor, and C. patzcuaro. In order to identify taxa, we carried out a cluster analysis applying euclidian distances, as well as a principal component analysis on the variance-covariance matrix. The results of the cluster analysis show four groups corresponding to each species, C. grandocule and C. patzcuaro being most similar between themselves and C. attenuatum the most different from the rest. Principal component analysis confirmed the separation of these species, defined by the angle formed by the jaws, the height of the dentary and the length of the post-articulate apophysis. These bones are related to the capture of food. Thus, the species of Chirostoma show clear morphological differentiation in the bony pieces of the mandibular region, a pattern that supports the hypothesis of trophic segregation that allows the coexistence of species in Lake Patzcuaro.