Tanystylum geminum Stock, 1954

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 : 42-43

publication ID

https://doi.org/ 10.11646/zootaxa.2319.1.1

DOI

https://doi.org/10.5281/zenodo.5327914

persistent identifier

https://treatment.plazi.org/id/03E687F8-296E-FF98-7ADC-17C89EE6FEC1

treatment provided by

Felipe

scientific name

Tanystylum geminum Stock, 1954
status

 

Tanystylum geminum Stock, 1954 View in CoL

Fig. 18–19 View FIGURE 18 View FIGURE 19

Tanystylum geminum Stock, 1954: 120 View in CoL .— Child 1979: 28. Stock: 13. Stock, 1982: 187. Stock 1986: 400. Müller 1990: 279. Müller 1992:45

Material. 19.— 2 fem. (gravid) ( SMF 1404 About SMF ), Thalassia , 5 l of substratum, 0.5–4 m, 27.VI.1985 . 1 fem. (gravid) ( SMF 1405 About SMF ), Thalassia , 5 l of substratum, 5.VII.1985 . 1 fem. (gravid) ( SMF 1406 About SMF ), Thalassia , 5 l of substratum, 9.IX.1985 . 1 male ( SMF 1407 About SMF ), Thalassia , 5 l of substratum, 8.XI.1985 . 2 males, 1 fem., 2 juv. ( SMF 1408 About SMF ), Thalassia , 5 l of substratum, 7.XII.1985 . 1 juv. ( SMF 1410 About SMF ), Thalassia , 5 l of substratum, 12.II.1986 .

24.— 2 males, 1 fem., 2 juv. ( ZMA 3387 View Materials ), Thalassia , 0.5–1 m, 8.XI.1985 . 1 juv. ( SMF 1411 About SMF ), Thalassia with corallinacean algae, 1 m, 21.I.1986 .

32.— 1 male ( SMF 1412 About SMF ), on brown algae (mainly Sargassum ) on rock, mesolittoral, 3.VIII.1985 .

34.— 1 fem. ( SMF 1413 About SMF ), on brown algae, Thalassia and hydroids, 0.5–2 m, 30.VII.1985 .

40.— 1 male (ov.), 5 fem. (gravid) ( SMF 1414 About SMF ), Thalassia , 1–3.5 m, 8.VIII.1985 .

43.— 1 male ( SMF 1415 About SMF ), Thalassia , 1–1.5 m, 25.II.1986 .

Description of male: Dorsal trunk outline circular, crurigers touching along their entire length, smooth and without any setae; all segments fused. Cephalon with two short antero-lateral setae above palp origin. Ocular process broader than high, eyes relatively large and distinctly pigmented. Abdomen relatively short, directed obliquely to the rear, with 4 short setae in its distal part; abdomen surpassing the 4 th crurigers by about 1/4–1/2 of its length. Proboscis relatively long, strongly narrowing in its distal third.

Cheliphores about 1/3 length of proboscis, fused in their median line, distally rounded and bearing 3–4 short setae. Palpus 4-articled, 2 nd article elongated; 4 th article two times as long as 5 th, bearing 6 ventral and 3 terminal spines. Oviger 10-articled; articles 4 and 5 elongated, of nearly equal length and bearing some short spines; articles 6–10 shortened, bearing some short spines.

Legs robust, all articles bearing conspicuously few short spines and setae; coxae 1 of all legs distallydorso-laterally with a few irregularly shaped (partly branched) tubercles with short spines; coxa 2 with some short lateral spines, some mounted on tiny tubercles; coxae 1–3 subequal in length; dorso-distal cement gland on femur forming short and distally narrowing tube; tibia1 and 2 subequal in length, with 2 flat roundish dorsal tubercles; tarsus as long as broad, 4 ventral spines; propodus moderately curved, with indistinct heel; proximal third of sole with 3 strong short spines; sole distally with 3 small spines and about 4 short setae; main claw feebly curved, half as long as propodus; auxiliaries nearly straight, 2/3 length of main claw.

In contrast to the brownish colouration of most other species in this genus, T. geminum in our samples is whitish-yellow.

Measurements: Trunk length 0.47; width (across 2 nd crurigers) 0.50; length of abdomen 0.13; proboscis length 0.34. Leg 3: coxa 1, 0.12; coxa 2, 0.13; coxa 3, 0.13; femur 0.34; tibia 1, 0.28; tibia 2, 0.30; tarsus 0.06; propodus 0.28; main claw 0.14; auxiliary 0.09.

Female: In habitus like male, coxae 1 and 2 of all legs with some short setae distally. Oviger distinctly shorter than in male, in total more sparsely spinose and articles 4–5 more shortened.

Remarks: T. geminum is easily recognizable by its well-developed cheliphores, lack of tubercles and setae on the crurigers, and light colouration in the samples. This species is strikingly similar to Tanystylum bredini Child, 1970 , which is widely distributed in the Indo-Pacific. Distinctly differentiating characters are the shape of the proboscis, which is more robust in T. bredini and distally not so strongly narrowing, and shorter than the palps. Stock’s (1982: 187) material from Somalia, which he considered with some reservation as T. geminum , is comparable to the T. bredini which Müller (1990c: 68, Figs. 7–10 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 ) reported and figured from Kenya.

T. geminum predominantly colonized Thalassia stands in the research area, although to a lesser degree it was found also in association with algae. The depth range was from the mesolittoral to about 4 m. A single ovigerous female was found in VII only. Mature specimens were found during the course of the entire year except in the months III and X–XI.

Distribution: Atlantic coast of Mexico and Panamá ( Child 1979: 28), Florida and Puerto Rico (Stock 1975a: 983), Barbados ( Müller, 1992), Martinique (Bourdillon 1955: 587; Müller 1990d: 279), Bonaire, Isla Margarita, St. Martin and Jamaica ( Stock 1979: 13).

Kingdom

Animalia

Phylum

Arthropoda

Class

Pycnogonida

Order

Pantopoda

Family

Ammotheidae

Genus

Tanystylum

Loc

Tanystylum geminum Stock, 1954

Müller, Hans-Georg & Krapp, Franz 2009
2009
Loc

Tanystylum geminum

Muller, H. - G. 1992: 45
Stock, J. H. 1986: 400
Stock, J. H. 1982: 187
Child, C. A. 1979: 28
1979
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