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M Chardon

Publications and source records attributed to M Chardon.

4 recordsLinked to original sources
PubMed2001

On the osteology and myology of catfish pectoral girdle, with a reflection on catfish (Teleostei: Siluriformes) plesiomorphies.

The configuration of the pectoral girdle bones and muscles of numerous catfishes was studied in detail and compared with that of other siluriforms, as well as of other teleosts, described in the literature. The pectoral girdle of catfishes is composed of only three bones, which probably correspond to the posttemporo-supracleithrum (posttemporal + supracleithrum), scapulo-coracoid (scapula + coracoid), and cleithrum of other teleosts. These latter two bones constitute the place of origin of the pectoral girdle muscles. Two of these muscles are related to the movements of the pectoral fin. These two muscles correspond, very likely, to the abductor superficialis and to the adductor superficialis of other teleostean fishes. In relation to the pectoral spine (thickened first pectoral fin ray), it is usually moved by three well-developed muscles, which are probably homologous with the arrector ventralis, arrector dorsalis, and abductor profundus of nonsiluriform teleosts. The morphological diversity and the plesiomorphic configuration of these muscles, as well as of the other catfish pectoral girdle structures, are discussed.

Animals↗
PubMed2000

Homologies among different adductor mandibulae sections of teleostean fishes, with special regard to catfishes (Teleostei: siluriformes).

The adductor mandibulae complex has been a subject of discussion and uncertainties due to a wide range of differentiations and fusions that have occurred during teleost evolution. The adductor mandibulae of numerous catfishes was studied in detail and compared with that of several other teleosts described in the literature. Our observations and comparisons demonstrate that: 1) the adductors mandibulae Aomega, A2, and A3 of acanthopterygians correspond, respectively, to the Aomega, A2, and A3 of ostariophysines; 2) the antero-dorso-lateral (A1) and the antero-ventro-lateral (A1-OST) sections of the adductor mandibulae present, respectively, in acanthopterygians and in basal ostariophysines are the result of two different patterns of differentiation of this muscle; 3) some derived ostariophysines present a lateral section of the adductor mandibulae attached to the upper jaw (A0) that is not homologous with any other section of this muscle present in any other ostariophysine or acanthopterygian fish; 4) the configuration of the adductor mandibulae present in Diplomystes seems to be the plesiomorphic condition for catfishes; and 5) the muscle retractor tentaculi, present in a large number of catfishes, is derived from the inner section of the adductor mandibulae (A3) and, thus, is not homologous with the lateral bundle of this muscle (A0) that inserts on the upper jaw in some derived ostariophysine fishes.

Anatomy, Artistic↗
PubMed1998

Distinctive anatomical features of the branchial basket in four carapidae species (ophidiiformi, paracanthopterygii).

The present study focuses on the branchial basket in four Carapidae species: Carapus acus, Encheliophis boraborensis, Encheliophis homei and Encheliophis gracilis. The aim is to highlight the skeletal and muscular features of the branchial basket, especially those that are believed to be related to their way of life and/or to be linked to the presence of primary sound-producing muscles. The space occupied by the primary sound-producing muscles between the neurocranium and the branchial basket gives rise to distinctive skeletal and muscular features. They prevent the 1st pharyngobranchials from becoming attached to the neurocranium in the normal way. These do not seem to play any role in the suspension of the upper pharyngeal jaws, as it is usually the case in teleosteans. The 1st epibranchials are separated from the 2nd pharyngobranchials. Ossified interarcual elements jointed to the 2nd pharyngobranchials and 1st epibranchials are found in the position usually occupied by the latter. The presence of primary sound-producing muscles gives rise to the need for the reorganisation of the musculature which is seen in particular with regards to the levatores branchiales. These are not found on the neurocranium but on the hyomandibular. The general skeletal and muscular data and the observations of the stomach contents suggest that the action of the branchial basket is restricted to carrying food in Carapus acus, Encheliophis boraborensis and Encheliophis homei, whereas it could also play a role in the work of cutting up soft food in Encheliophis gracilis.

Animals↗