Striated muscles of the black basses (Micropterus, Centrarchidae): Myological stasis in a generalized group of percomorph fishes

Abstract

Striated muscles of a generalized genus of percomorph fishes (Micropterus, Centrarchidae, Percomorpha) were described. Overall, myological variation was sparse among species of black bass. Variation took the form of minor variants in the size or shape of a muscle or of singular or incongruous variants characterized by abnormalities in a single specimen. The remaining myological variation occurred as mimicking variants and was shared irregularly among taxa. The lack of myological variation among black bass may well be correlated with the low degree of diversity exhibited in their ecology, life history, and external anatomy. However, the value of Micropterus in systematic and evolutionary studies is not compromised by morphological stasis. Instead, because Micropterus and other conserved lineages have been minimally responsive to ecological factors, they are valuable as outgroups to polarize character states, as identifiers of vicariant events leading to allopatric speciation, and as exemplars for studying the evolutionary mechanism of stabilizing selection. In addition, the description and assessment of myological variation in this generalized percomorph will be useful in future studies of comparative anatomy, functional morphology, and higher level systematics.