Morphology of the pectoral girdle in Pomatoschistus lozanoi De Buen, 1923 (Gobiidae), in relation to pectoral fin adduction

SUMMARY Like most gobies, Pomatoschistus lozanoi is a benthic fish species. During locomotion the pectoral fin adductlon is of great importance in generatng a forward propulsion. Several specimens of Pomatoschistus lozanoi were dissected, cleared with staining and sectioned with staining, in order to examine the morphology of the pectoral girdle apparatus. In this paper a detailed description is given of the skeletal elements, the musculature and the ligaments of the pectoral girdle apparatus. The pectoral fins of gobies seem better adapted to powerful adduction than a generalised teleost. The proximal radials form a large rigid shoulder plate with a long distal margin on which a high pectoral fin articulates. The fin muscles are strongly developed and assure, together wilt the large pectoral fin, powerful drag based pectoral propulsion. The morphological adaptations for powerfull adduction, however, are at cost of the maneuvering abilities of the pectoral fins.