Abstract: Research was conducted on stargazer fish length 13-19 cm and body weight 70-115 g caught in the Novigrad sea area (Croatia). An average diameter of muscle fibers in trunk muscle dorsal of the horizontal septum (dorsal muscle) was slightly greater than in the trunk muscle ventral of the horizontal septum (ventral muscle). The greatest mean fiber diameter was measured in dorsal muscle of stargazer total length 19 cm and it was 112.33 μm and in ventral muscle 109.25 μm (diameters of muscle fibers in dorsal and ventral muscle were 41-150 μm). The smallest mean fiber diameter was measured in stargazer total length 13 cm in the dorsal muscle 70.27 μm and in ventral muscle 64.95 μm (diameters of muscle fibers in dorsal and ventral muscle were 11-120 μm). The statistical significant (p<0.05) differences were determinate for changes in diameter of muscle fibers in dorsal muscle between 15.5, 16, 17.5, 18, 18.5 and 19 cm total length. In the ventral muscle statistical significant (p<0.05) differences were determined only between 15.5, 16, 17.5 and 18 cm total length of examined fish. Very low activity of Succinic acid Dehydrogenase (SDH), Lactic acid Dehydrogenase (LDH) and alkaline stable Adenosintriphosphatase (ATP) moderate to high activity of acid stable Adenosintriphosphatase (ATP) and larger amount of glycogen suggests that muscle fibers are white fast twitch glycolytic fibers. The activity of LDH and SDH as well of the alcaline stable ATP was strong but activity of acid stable ATP was weak in red slow twitch oxidative muscle fibers. The red fibers were placed superficially at the lateral side of the body as dark muscles clearly distinguished from the white ones but in stargazer small red and intermediary muscle fibers runs as a band into white dorsal muscle. The intermediary (pink) oxidative glycolytic muscle fibers has got larger fiber diameter then red and moderate to strong activity of SDH, LDH, acid and alcaline stabile ATP. The total number of fibers of stargazer fish was increased (hyperplasia) till total length of fish reached 15.5 cm (77 g). In the some time muscle fiber diameter of dorsal muscle was progressive increased from 14 cm (74 g) to 19 cm (115 g) (hypertrophy) and very similar observation was in muscle fiber diameter of ventral muscle.
S. Nejedli, Z. Kozaric, Z. Matasin and I. Tlak Gajger, 2012. Histomorphology of Trunk Muscles of Stargazer (Uranoscopus scaber, Linnaeus 1758). Journal of Animal and Veterinary Advances, 11: 572-577.