Caenopedina

Anderson, Owen F., 2009, The giant purple pedinid — a new species of Caenopedina (Echinodermata: Echinoidea: Pedinidae) from New Zealand and Australia, Zootaxa 2007, pp. 43-57 : 53-54

Key to the extant species of Caenopedina

The first key to the Caenopedina was provided by Clark (1912). This distinguished the five species then known ( C. cubensis , C. indica , C. hawaiiensis , C. mirabilis , and C. pulchella ) mainly on differences in the colour of the apical disc, tuberculation of the genital plates, and primary spine form, colour, and banding. Mortensen (1940b) produced a revised key, based on that of Clark (1912), to incorporate five additional species ( C. capensis , C. diomedeae , C. annulata , C. superba , and C. depressa ). In this key C. capensis was set apart owing to its almost straight pore series, a feature considered primitive by Mortensen (1940b), whereas the other new species were either similar to existing species or, in the case of C. depressa , poorly known. A further revised key is provided below, based on those of Clark (1912) and Mortensen (1940b), to accommodate the four antipodean species described between 1964 and the present new species. Caenopedina depressa (from the Indian Ocean) is most similar to C. superba , but is poorly known and thus excluded from the key. Additional characters used in the key are the shape of the interambulacral plates and the presence of sexual dimorphism in the genital pores.

1 Primary spines long and slender, may exceed 1.5 times the maximum diameter of the test........................................ 2

- Primary spines short, thick, and smooth; not exceeding 1.5 times the maximum diameter of the test ...................... 12

2 Pores of the tube feet arranged in nearly straight vertical series; (tubercles well spread over genital plates except for lateral and outer margins; test and secondary spines whitish; apical disc, upper coronal plates, and primary spines purple) .......................................................................................................................................................... C. capensis

- Pores arranged more or less in distinct arcs of three .................................................................................................... 3

3 Interambulacral plates short and wide, with large areas on either side of the central primary tubercle filled with smaller tubercles ........................................................................................................................................................... 4

- Interambulacral plates narrow with little room on either side of the central primary tubercle for smaller tubercles .. 5

4 All spines coloured pink and yellowish-lime, males with elongate genital pores extending as a channel down the interambulacral midline; about 20 tubercles on each genital plate, outer regions naked ........................ C. alanbakeri

- All spines a rich brown colour, genital pores circular and exhibiting no sexual dimorphism; genital plates with about 40 tubercles, only narrow marginal regions naked; large (test diameter up to 100 mm)................... C. porphyrogigas

5 Primary spines banded green and red/brown, or green, red/brown and white.............................................................. 6

- Primary spines unbanded .............................................................................................................................................. 9

6 Tubercles of genital plates entirely or almost entirely limited to the adapical edge..................................................... 7

- Tubercles of genital plates not limited to the adapical edge ......................................................................................... 8

7 Periproctal plates bearing tubercles; apical system a distinctive green; test white but adapical plates light brownish green; one or two tubercles may be present away from adapical edge of genital plates (secondary tubercles white, some with greenish tips) ................................................................................................................ C. novaezealandiae

- Periproctal plates usually without tubercles; apical system reddish brown; test with a rosy tint, sometimes light green ........................................................................................................................................................................ C. indica

8 Primary spines with numerous, narrow, well limited bands; ophicephalous pedicellariae with short, not constricted blade; tubercles of the genital plates arranged in an inner and outer band, separated by a broad naked belt................. .................................................................................................................................................................... C. annulata

- Primary spines with fewer, broad, not well limited bands; ophicephalous pedicellariae with long constricted blade; tubercles of the genital plates forming an inner band and others scattered centrally ................................. C. mirabilis

9 Tubercles of genital plates not limited to the adapical edge ....................................................................................... 10

- Tubercles of genital plates limited to the adapical edge ............................................................................................. 11

10 Primary spines of adult greenish or whitish, widened distally; tubercles scattered relatively evenly over genital plates ............................................................................................................................................................ C. cubensis

- Primary spines of adult dull reddish fading to greenish yellow at tip, not widened distally; tubercles of genital plates concentrated around (but not limited to) perimeter of periproct; (test purplish, especially on apical system; secondary spines light coloured, colours constant between individuals)................................................................ C. hawaiiensis

11 Spines white or greenish white; apical system whitish with faint purple markings ................................ C. diomedeae

- Spines reddish brown; apical system dark purplish, nearly black; (females with multiple (3 to 6) genital pores on each genital plate) .................................................................................................................................... C. otagoensis

12 Periproctal plates few and large; apical plates brownish-rose, conspicuously sculptured in centre; secondary spines white or reddish-white ............................................................................................................................... C. pulchella

- Periproctal plates numerous, small; aboral plates including apicals reddish-white, not distinctly sculptured; secondary spines dull red or green; (periproct and oral side of test including peristome white; primary spines white basally becoming greenish distally; colours may differ in juveniles) ...................................................................... C. superba