Anoplodactylus petiolatus (Krøyer, 1844), Hedgpeth, 1948

Müller, Hans-Georg & Krapp, Franz, 2009, The pycnogonid fauna (Pycnogonida, Arthropoda) of the Tayrona National Park and adjoining areas on the Caribbean coast of Colombia 2319, Zootaxa 2319 (1), pp. 1-138 : 110-112

Anoplodactylus petiolatus (Krøyer, 1844)

Fig. 58

Phoxichilidium petiolatum Krøyer 1844: 123 .

Anoplodactylus petiolatus (Krøyer 1844) Hedgpeth 1948: 22 ; literature. Sawaya 1950: 73. Stock 1951: 16. Stock1957: 85. Bacescu 1959: 117. Stock 1958: 4. Stock 1962: 218. Stock 1966: 52. Arnaud 1973: 151. Kraeuter 1973: 495. Krapp 1973: 72. Stock: 1072. Arnaud: 69. Krapp & Kraeuter 1976: 338. Stock 1978: 216. Child 1982: 21. Arnaud 1987: 45. Stock 1987: 514. Schüller 1989: 290.

Anoplodactylus guyanensis Child 1977: 591 . Stock 1986: 404.

Material: 9.— 1 male (ov.) ( SMF 1170 ), coral rubble, 13 m, 3.VI.1985 . 1 male ( INVEMAR), coral rubble, 12 m, 29.XI.1985 . 1 male ( ZSM), coral rubble, 12–15 m, 15.XII.1985 . 1 male (ov.), 1 fem. (gravid) ( SMF 1171 ), coral rubble, 22 m, 17.XII.1985 . 1 male ( SMF 1172 ), coral rubble, 20–22 m, 26.I.1986 . 1 male (ov.) ( ZFMK), under blocks of stone, 1–2 m, 4.II.1986 . 1 fem. ( SMF 1173 ), coral rubble, 5–6 m, 14.III.1986 .

12.— 1 male ( ZMA 3359 ), coral rubble, 17–19 m, 9.I.1986 .

13.— 1 male, 1 juv. ( SMF 1174 ), coral rubble, 21 m, 8.XI.1985 .

14.— 1 male, 1 fem. (gravid), 2 juv. ( SMF 1175 ), 1.5–5 m, 7.I.1986 .

Description of male: Dorsal trunk outline oval, rather slender, all segments fused. All crurigers bearing a dorso-distal stumpy tubercle, which is variably developed. Ocular process twice higher than basal diameter, eyes distinctly pigmented. Abdomen almost twice higher than ocular process, slender, directed obliquely backwards, usually bearing 2 short distal setae. Proboscis relatively slender, cylindrical, parallel-sided over almost entire length, obtusely ending.

Cheliphore slender, scape longer than proboscis; chela slender, cutting edges toothless; movable finger on inner as well as on outer face with a seta. Ovigers slender; 3 rd article the longest, 1/3 longer than first and second together; fourth article 1.2 times as long as fifth and sixth together; terminal article the shortest, distally obtusely rounded, last two articles with 5 short setae on inner face directed proximally.

Legs slender and sparsely setose; coxa 1 just shorter than coxa 3, with flat dorso-distal tubercle; coxa 2 twice length of coxa 1, with a short round ventro-distal genital process on legs 3–4; femur the longest article, with long dorso-distal seta; dorso-median cement gland duct on femur a slender tube, directed obliquely anteriorly, at mid-length of femur; tibia 1 and tibia 2 of almost equal length, with long dorso-distal seta, that on tibia 2 distinctly farther away from distal end of article; tarsus as long as broad, ventrally with a slender spine and 2–3 short setae; propodus distinctly curved, heel distinctly developed, but variable in shape, with 2– 4 spines; sole almost straight, proximal half with 3–4 short and distally-curved spines, distal half with a relatively long cutting lamella, about half of sole length; main claw slightly curved, slender, its tip reaching the tips of the spines on distal margin of heel; auxiliary claw almost straight, about 1/8 length of main claw.

Measurements: Trunk length 0.93; width 0.59 (across first crurigers); length of abdomen 0.25; length of proboscis 0.33. Length of cheliphore scape 0.33; length of chela 0.17. Lengths of articles of leg 3: coxa 1— 0.16; coxa 2—0.36; coxa 3—0.19; femur 0.62; tibia 1—0.54; tibia 2—0.56; tarsus 0.06; propodus 0.30; main claw 0.22; auxiliary claw 0.03.

Female: like male apart from the sex-specific characters.

Remarks: The species is closely related to Anoplodactylus maritimus Hodgson, 1914 (incl. Anoplodactylus parvus Giltay, 1934 ) which is widely distributed in tropical and moderate Atlantic, but is distinguished by a more slender habitus, more slender and less curved chela fingers, a longer cement gland duct and a longer cutting lamella on the propodus (comp. Stock 1975a: 1073, Fig. 54 ). The characters Child (1977b: 591) claimed for A. guyanensis from the northern coasts of South America are within the variability of petiolatus , so guyanensis is regarded as a junior synonym of this species.

In the Santa Marta region A. petiolatus definitely preferred coral rubble habitats, its depth distribution ranged from 1– 22 m. Only 3 ovigerous males were collected.

According to published data A. petiolatus does not prefer definite substrata, but seems to avoid seagrass beds. In total its depth distribution reaches from the surf zone down to about 1520 m.

Distribution: Temparate to tropical Atlantic, European Mediterannean; a compilation of its distribution is given in Stock (1986: 404).

Figures

FIGURE 54. Anoplodactylus jonesi Child, 1974, gynandromorph: A trunk dorsal, B trunk lateral, outline of rudimentary eye process above,.C chela, D oviger, E leg 3, F propodus and tarsus of leg 3, G cement gland duct on leg 3.

FIGURE 58. Anoplodactylus petiolatus (Krøyer, 1864), male: A trunk dorsal, B trunk with oviger, lateral, C trunk lateral, another specimen, D proboscis outline ventral, E chela, F three distal oviger articles, G leg 4, H propodus and tarsus of leg 4, I propodus and tarsus of leg 3, J two different cement gland ducts.