Class CHONDRICHTHYES
Introduction
The class Chondrichthyes includes two subclasses, the Holocephali (chimaeras) and the Elasmobranchii (all other sharks and rays).
Relationships of the subclass Elasmobranchii have been the subject of extensive studies, but no full concensus has been reached. Major works include those of Compagno (1977, 1988), Shirai (1992, 1996), Last & Stevens (1994) and Carvalho (1996). Tentatively, for the sharks the classification of Nelson (1994) is followed here. Among the rays, Nelson (1994) recognised a single order, Rajiformes, with four suborders, but the system of McEachran & Aschliman (2004) is followed here with each group regarded as a distinct order. Some workers still recognise only a single order of skates and rays with up to 13 suborder (Compagno et al. 2005). McEachran et al. (1996) recognised six orders for the rays, dividing the Rajiformes into Rajiformes, Rhiniformes and Rhynchobatiformes, but subsequently McEachran & Aschliman (2004) recognised only five orders of rays and that is followed here. The classification is similar to that followed by Hoese et al (2006), except that the Rhinobatiformes is separated from the Rajiformes. Nelson (2006), however, presented a classification similar to the one used here, differing largely in the number of recognised families. Differences between the classification used here and that of Nelson's (2006) are noted in the appropriate family or order introductions later in this volume. Compagno (1999) provided a checklist of species.
General References
Carvalho, M.R. de 1996. Higher-level elasmobranch phylogeny, basal squaleans, and paraphyly. pp. 35-62 in Stiassny, M.L.J., Parenti, L.R. & Johnson, G.D. (eds). Interrelationships of Fishes. San Diego : Academic Press 496 pp.
Compagno, L.J.V. 1977. Phyletic relationships of living sharks and rays. American Zoologist 17(2): 303-322
Compagno, L.J.V. 1988. Sharks of the Order Carcharhiniformes. Princeton, New Jersey : Princeton University Press 572 pp.
Compagno, L.J.V. 1999. Checklist of living elasmobranchs. In, Hamlett, W.C. (ed.). Sharks, Skates, and Rays: the Biology of Elasmobranch Fishes. Baltimore & London : John Hopkins University Press 515 pp.
Compagno, L.J.V., Last, P.R., Stevens, J.D. & Alava, M.N.R. 2005. Checklist of Philippine Chondrichthys. CSIRO Marine Laboratory. Report 243: 1-103
Hoese, D.F. & Larson, H.L. in Hoese, D.F., Bray, D.J., Paxton, J.R. & Allen, G.R. 2006. Fishes. In, Beesley, P.L. & Wells, A. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing : Australia Part 1, pp. xxiv 1–670; Part 2, pp. xxi 671–1472; Part 3, pp. xxi 1473–2178
Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls
McEachran, J.D. & Aschliman, N. 2004. Phylogeny of Batoidea. pp. 79-113 in Carrier, J.C., Musick, J.A. & Heithaus, M.R. (eds). Biology of Sharks and their Relatives. Boca Raton, Florida : CRC Press 596 pp.
McEachran, J.D., Dunn, K.A. & Miyake, T. 1996. Interrelationships of the batoid fishes (Chrondrichthyes: Batoidea). pp. 63-84 in Stiassny, M.L.J., Parenti, L.R. & Johnson, G.D. (eds). Interrelationships of Fishes. San Diego : Academic Press 496 pp.
Nelson, J.S. 1994. Fishes of the World. New York : John Wiley & Sons 600 pp.
Nelson, J.S. 2006. Fishes of the World. Hoboken, New Jersey : John Wiley & Sons, Inc. 601 pp.
Shirai, S. 1992. Squalean Phylogeny. A new framework of "squaloid" sharks and related taxa. Sapporo : Hokkaido University Press 151 pp.
Shirai, S. 1996. Phylogenetic interrelationships of neoselachians (Chondrichthyes, Euselachii). pp. 9-34 in Stiassny, M.L.J., Parenti, L.R. & Johnson, G.D. (eds). Interrelationships of Fishes. San Diego : Academic Press 496 pp.