bones of the pectoral girdle skeleton in representatives of 48 genera in 41 families of eurypterygian fishes were studied. the structure and position of the pectoral girdle is relatively stable in eurypterygians. it consists of the extrascapula, posttemporal, supracleithrum, cleithrum, postcleithrum, scapula, coracoid, actinosts, and fin rays. an ectocoracoid is present in some gasterosteiforme...

The paired pelvic fins in fishes have been the subject of few studies. Early work that amputated pelvic fins concluded that these fins had very limited, and mainly passive, stabilizing function during locomotion. This paper is the first to use three-dimensional kinematic analysis of paired pelvic fins to formulate hypotheses of pelvic fin function. Rainbow trout (Oncorhynchus mykiss) were filme...

Jawed vertebrates (gnathostomes) have undergone radical anatomical and developmental changes in comparison with their jawless cousins (cyclostomes). Key among these is paired appendages (fins, legs and wings), which first evolved at some point on the gnathostome stem. The anatomy of fossil stem gnathostomes is, therefore, fundamental to our understanding of the nature and timing of the origin o...

Among osteichthyans, basal actinopterygian fishes (e.g. paddlefish and bowfins) have paired fins with three endoskeletal components (pro-, meso- and metapterygia) articulating with polybasal shoulder girdles, while sarcopterygian fishes (lungfish, coelacanths and relatives) have paired fins with one endoskeletal component (metapterygium) articulating with monobasal shoulder girdles. In the fin-...

Classical hypotheses regarding the evolutionary origin of paired appendages propose transformation of precursor structures (gill arches and lateral fin folds) into paired fins. During development, gnathostome paired appendages form as outgrowths of body wall somatopleure, a tissue composed of somatic lateral plate mesoderm (LPM) and overlying ectoderm. In amniotes, LPM contributes connective ti...

study of the osteological development in fishes is important from fisheries, biology and aquaculture points of views. it can be used as an early bio-indicator of non-optimal rearing conditions. the caspian roach, rutilus caspicus is a native cyprinid fish of the caspian sea that its artificial propagation has fulfilled in hatcheries to recruit its natural stocks. hence, this study was conducted...

Chondrichthyans (sharks, skates, rays and holocephalans) possess paired appendages that project laterally from their gill arches, known as branchial rays. This led Carl Gegenbaur to propose that paired fins (and hence tetrapod limbs) originally evolved via transformation of gill arches. Tetrapod limbs are patterned by asonic hedgehog(Shh)-expressing signalling centre known as the zone of polari...

In order to improve the performance of AUVs in terms of efficiency and maneuverability, researchers have proposed biomimetic propulsion systems that swim using flapping fins rather than rotary propellers. This calls for the exploration of unique locomotion characteristics found in a variety of fish for use in underwater robots. (Sfakiotakis et. al., 1999) present a good review of fish swimming ...

Gliding adaptations in thoracopterid flying fishes represent a remarkable case of convergent evolution of overwater gliding strategy with modern exocoetid flying fishes, but the evolutionary origin of this strategy was poorly known in the thoracopterids because of lack of transitional forms. Until recently, all thoracopterids, from the Late Triassic of Austria and Italy and the Middle Triassic ...