The Morphology of the Head-Muscles of a Generalized Haplochromis Species: H. Elegans Trewavas 1933 (Pisces, Cichlidae)

Abstract

This paper, dealing with the morphology (viz. structure, insertion areas, direction and, to a lesser degree, shape) of the head muscles of Haplochromis elegans, is the second study in a series on the head-morphology of this generalized Haplochromis species from the East-Africa Lakes Edward and George. The shape-descriptions of the skeletal elements, given in the first paper of the series (BAREL et al., 1976), have been used for an accurate definition of the position of the muscles. As well as dissection, graphical reconstructions from serial sections were necessary for an adequate description, especially of the small and complicated branchial muscles. The aim of the series is a basic description of the head-morphology of a generalized Haplochromis species suitable for comparative studies on the functional morphology of cichlid fishes. Therefore the muscle-descriptions deal with aspects relevant to functional morphology and generally do not enter upon questions of formal comparative morphology, viz. homology and related subjects.

Kinematics of mouthbrooding inOreochromis niloticus(Cichlidae)

“…This can be explained by the opercular region of the gill slit being opened actively (i.e. by force from the dilatator operculi and levator arcus palatini muscles; Anker, 1978) and closed actively (i.e. by force of the adductor opercula and the adductor arcus palatini muscles; Anker, 1978), while the ventral region acts purely as a passive valve.…”

“…by force from the dilatator operculi and levator arcus palatini muscles; Anker, 1978) and closed actively (i.e. by force of the adductor opercula and the adductor arcus palatini muscles; Anker, 1978), while the ventral region acts purely as a passive valve. Suction will be created during the opercular abduction phase, resulting in a lower water pressure inside compared with outside the head.…”

The biological control of snail intermediate hosts of schistosomiasis by fish

“…Hoogerhoud (1986b) found that the horn width of the LPE is a good measure to differentiate between animals with a hypertrophied and a reduced LPE. The muscle complex attached to the LPE, the musculus levator externis 4 and the musculus levator posterior (mLE4/LP), were removed, dried and weighed (muscular and skeletal names according to Anker, 1978, andBarel et al, 1976).…”

The trophic ecology, functional morphology and phylogeny of the hemiramphidae (beloniformes)

“…Several muscles could not be identified from the descriptions given in Winterbottom's work. These were ascribed names with the assistance of work on cichlid pharyngeal anatomy (Anker, 1978;Stiassny, 1981).…”

“…This muscle, which linked a pharyngobranchial element to the skull base, is probably derived from the transversus dorsalis muscle block, and may be distinguished from the levatores interni by its more median origin on the cranium. Considering this, and its central origin in the pharynx, it is named (using Anker's (1978) terminology) the muscularis cranio-pharyngobranchialis 2 posterior.…”