Original paper
Morphogenesis and function of the squamation in sharks
Reif, W. E.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 164 Heft 1-2 (1982), p. 172 - 183
28 references
published: Dec 22, 1982
DOI: 10.1127/njgpa/164/1982/172
ArtNo. ESP155016401040, Price: 29.00 €
Abstract
In order to analyze the hydrodynamic efficiency of shark scales, two methods can be employed: a) the study of possible correlations between scale types and different life habits, and b) the experimental and theoretical explanation of the scale patterns which are found in the fastest sharks. Method (a) will be discussed here, for method (b) see Reif & Dinkelacker, this volume. There are very few reliable figures of scale shapes in the literature and those publications which figure individual scales never take the ontogenetic and regional differentiation of the squamation into account (see, however, Reif, 1973, 1974). To ovcrcome this situation the present author is currently preparing a SEM-atlas of shark scales. So far, photos have been taken from the squamation of 40 species. The data which are given below are based on this atlas and on figures in Bigelow & Schroeoer (1948). Shark scales can have four different functions: a) protection against injury and abrasion by rocky substrates, b) protection against parasites, epibionts and (in certain cases) predators; c) drag reduction in fast swimming sharks by influencing the viscous sublayer of the boundary layer (Reif & Dinkelacker, this volume); d) providing space for photophores in luminescent sharks. Rostral "teeth", which are in reality specialized scales, will not be discussed here.
Keywords
neoselachians • Triassic • durophagous reef dwellers • demersal sharks • batoids