The brain organization of butterflyfishes

Abstract

SynopsisThe encephalization indices of angelfishes (Pomacanthidae) and butterflyfishes (Chaetodontidae) are typical of advanced perciform fishes: both families lie in the upper part of the polygon of teleost indices, The chaetodontids seem to be a little more encephalized than pomacanthids. The general morphology of the brains in both families is very similar: small olfactory bulbs, large optic tectum and a cerebellum which covers the brain structures in front of it like a cap. This morphology is shared by another family of the coral reef biotope, the Acanthuridae, The histological architecture is also typical of advanced teleosts, with a cortexlike pallium, a laminated nucleus geniculatus (= pretectalis superficialis), a complex valvula cerebelli and a corpus glomerulosum with a clear neuropile centre. The quantitative analysis of the main subdivisions of the brain, either from relative volumes or from indices, shows small olfactory bulbs (microsmy) but important telencephalic and diencephalic centres, large tectal centres (vision) and large cerebellum (precise locomotion). Many of these peculiarities are shared by other fishes inhabiting coral reefs. The differences between the two families seem to be primarily correlated with food habits: the angelfishes, which are sponge-feeders and may have an overweight due to the ballast of the sponge-skeleton in their digestive tract, and which do not need either such good vision or such precise locomotion to pick up their prey, could be a little less encephalized than the butterflyfishes.

Histopathological changes in the Brain Tissue of Africa Catfish exposure to Glyphosate Herbicide

“…For example within North American catostomids (Miller and Evans, 1965), African Great Lakes cichlids (Huber et al, 1997), and deep-sea eels and grenadiers (Wagner, 2002), the interspecific variation in sensory and association areas of brains is tightly correlated with ecology, especially habitat and feeding. However in some European cyprinids (Kotrschal and Palzenberger, 1992) and coral reef dwelling perciform angelfish and butterflyfishes (Bauchot et al, 1989), interspecific variation is not as pronounced and the link between brain morphology and ecology is less robust. In a comprehensive review of this field, Kotrschal et al, (1998) noted that primary sensory areas of the brain relate more closely to feeding whereas integration centers reflect differences in microhabitat, and in phyletically advanced teleosts like perciforms there is a relative shift of brain mass from sensory areas to integration centers.…”

Diversity of monogenean parasites in belonid fishes off the Mediterranean Sea with redescription of Aspinatrium gallieni Euzet and Ktari, 1971 and Axine belones Abildgaard, 1794

“…Belonid fishes were represented in Tunisian coast by B. belone, B. svetovidovi and T. a. imperialis [22,24].…”

“…Fish were caught by local fishermen using gillnets from the eastern Tunisian coast, at the central area [Mahdia (35°30' N, 11°3' E), Sousse (35°50' N, 10°38' E), Monastir (35°46' N, 10°49' E) and Chebba (35°14' N, 11°8' E)] and at the southern area [Sfax (34°47' N, 10°49' E), Kerkennah (34°37' N, 11°6' E), Gabes (33°56' N, 10°4' E), Jerba (33°46' N, 10°44' E) and Zarzis (33°30' N, 11°7' E)]. Specimens were identified using the methods of Collette and Parin [21] and Bauchot [22].…”

Gene expression correlates of social evolution in coral reef butterflyfishes

“…one week). Brain regions, identified using a butterflyfish brain atlas 102,103 , were manually extracted at -30˚C using a hand-held micro-punching device (50mm diameter; Stoelting, model # 57401) (Fig. 2), incubated in RNAlater® at 4˚C over night, and then stored at -20˚C for up to one week.…”