Comparative study of dentition among species ofPoecilia (Pisces)

Abstract

Many studies in the genus Poecilia have focused on reproductive and genetic characteristics of Poecilia formosa, the Amazon molly, and its sympatric species P. latipinna and P. mexicana. The research literature of Poecilia dentition has been limited to general tooth morphology. Essentially absent are comparative analyses of dentition patterns and total numbers of teeth. The current study uses dentition analysis as a method to compare species in the genus Poecilia and to address some taxonomic issues related to these fish. The study focused on fish from the areas of southern Texas and northeastern Mexico. Through the use of scanning electron microscopy, the lower jaws of Poecilia spp were examined to determine total numbers of outer and inner teeth. In addition, the differences in distribution patterns of the inner teeth were recorded and compared. Statistical analyses were performed to determine which comparisons were significant. This study reveals several observations: 1) variations in the numbers of outer and inner teeth exist in some of these fish with respect to site of collection; 2) differences in total teeth numbers and dentition patterns were found both interspecifically and intraspecifically; and 3) in addition, dentition analysis provided evidence regarding the origin of P. formosa. This study supports the current notion that P. latipinna, the proported paternal component, and P. mexicana limantouri, the purported maternal component, are the progenitor species of P. formosa. Two unresolved taxonomic questions were addressed through dentition analysis. First, the present study supports the exclusion of the triploid associate of P. formosa as a separate species from P. formosa. Second, this study shows a significant difference in the number of inner teeth and in dentition patterns between P. mexicana limantouri and P. mexicana mexicana. Such differences, in addition to previously known distinguishing characteristics, should prompt careful consideration of whether or not these taxa deserve specific status or retention of their current subspecific status. J. Morphol. 239:271–282, 1999. © 1999 Wiley‐Liss, Inc.

Ontogenetic transition from unicuspid to multicuspid oral dentition in a teleost fish: Astyanax mexicanus, the Mexican tetra (Ostariophysi: Characidae)

“…Features of bony fish dentitions often change during ontogeny (Howes & Sanford, 1987; Nakajima & Yue, 1989, 1995; Hahn, Pavanelli & Okada, 2000; Murray, 2004), and differences within (Roberts, 1974; Meyer, 1990; Caldecutt, Bell & Buckland‐Nicks, 2001; Tigano et al ., 2001; Trapani, 2003, 2004) and between (Parenti & Thomas, 1998; Lewis et al ., 1999) taxa may often track ecological specializations (Sage & Selander, 1975; Motta, 1989; Blaber, Brewer & Salini, 1994; Kanda & Yamaoka, 1995; Mullaney & Gale, 1996). While teeth in adult fishes have been relatively well‐studied (e.g.…”

Phenotypic Variation in an Asexual-Sexual Fish System: Visual Lateralization

“…Fischer and Schlupp, 2009 Morphology (dentition) Amazon molly vs. sailfin molly vs. Atlantic molly Number of upper and lower teeth differs significantly between all species*. Lewis et al, 1999 Morphology (…”

Are you more than the sum of your parents’ genes? Phenotypic plasticity in a clonal vertebrate and F1 hybrids of its parental species

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