Chimaera

Kemper, Jenny M., 2017, New species of Chimaera (Chondrichthyes: Holocephali: Chimaeriformes: Chimaeridae) from the Southwestern Indian Ocean, Zootaxa 4312 (1), pp. 1-37 : 31-32

Key to Indian Ocean Chimaera species

The following key to Indian Ocean Chimaeras is a modification of Ebert (2014), and includes the three new species described here. A few caveats relative to this key; many Chimaera species share similar body coloration, but color can vary greatly within species. Therefore, the key groups species based on the most consistent and reliable characteristics, including body coloration characters, such as silvery or not silvery, and the presence or absence of distinct patterning on the body. Branching of oral and preopercular canals is not included in the key since this characteristic was determined to be inconsistent within a species.

1a. Body color silvery.....................................................................................2

1b. Body color not silvery..................................................................................3

2a. Dorsal-fin spine exceeding apex of first dorsal fin; trunk lateral line with tight sinuous undulations or broad undulations anterior to pelvic fins; prepelvic tenaculum of males with 4–5 denticles, claspers of mature males exceeding free tips of pelvic fins..................................................................................... Chimaera argiloba

2b. Dorsal-fin spine not exceeding apex of first dorsal fin; trunk lateral line without sinuous undulations along its length; prepelvic tenaculum of males with 6–7 denticles, claspers of mature males not exceeding free tips of pelvic fins...... Chimaera fulva

3a. Dorsal-fin spine small, not exceeding height of first dorsal fin, and fairly straight...................................4

3b. Dorsal-fin spine large, exceeding height of first dorsal fin, robust, slightly to strongly curved.......................... 6

4a. Long slender body, conical snout; pelvic fins relatively small, and not distinctly rounded; body color light tan............5

4b. Robust body, massive, blocky head, blunt squared snout; pelvic fins large and rounded; body color grey-blue, purple-brown or lavender............................................................................... Chimaera lignaria

5a Suborbital ridge well defined, eyes very large; dorsal spine thin, and very straight, second dorsal fin moderately long, mouth distinctly dark, uniform light tan color, not iridescent............................. Chimaera buccanigella new species

5b. Very slender body, shorter snout, suborbital ridge poorly defined; eyes fairly large; dorsal spine robust, slightly curved; second dorsal fin very long; mouth with some dark marking, uniform light toffee-tan color, not iridescent................................................................................................... Chimaera didierae new species

6a. Medium to small sized head, conical snout, without well-defined suborbital ridges..................................7

6b. Large, blocky head, well-defined suborbital ridge, blunt, squared snout; dorsal spine thick, slightly curved, exceeds the apex of the first dorsal fin; body color brown, marbled around snout; posterior margin of first dorsal fin often distinctly white................................................................................. Chimaera willwatchi new species

7a. Eyes moderate in size, greater than one-third head length, dorsal spine one-third to one-fourth BDL; body color uniform dark brown or black....................................................................... Chimaera macrospina

7b. Eyes small, less than one-third head length, dorsal spine one-fourth to one-seventh BDL; body color blackish-brown........................................................................................... Chimaera notafricana