Hemichela Stock, 1954
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publication ID |
https://doi.org/ 10.12782/specdiv.23.215 |
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persistent identifier |
https://treatment.plazi.org/id/E818FE05-FFC4-FFDD-FEE4-FAC5FDD73948 |
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treatment provided by |
Felipe |
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scientific name |
Hemichela Stock, 1954 |
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Genus Hemichela Stock, 1954 View in CoL Hemichela nanhaiensis Wang et al., 2015 ( Figs 1 View Fig , 2 View Fig )
Material examined. 1 female (ICHUM-5435), 32°14.97′N, 129°28.32′E, west of Hirajisone , East China Sea, 405 m, 7 March 2009 GoogleMaps . 1 male carrying eggs (ICHUM- 5436), 28°33.605′N, 127°02.676′E, off Amami , East China Sea, 619–635 m, 17 November 2011 GoogleMaps . 1 male (ICHUM-5437), 28°33.576′N, 127°02.616′E, off Amami , East China Sea, 625–629 m, 18 November 2011 GoogleMaps . 1 female (ICHUM-5438), 28°33.601′N, 127°02.457′E, off Amami , East China Sea, 608–618m, 19 November 2011 GoogleMaps . All specimens were collect- ed by K. Kakui.
Amended diagnosis. Lateral processes long, width across second processes more than 1.45; outgrowths on lateral processes unbranched, each bearing distal spinules; movable finger of chelifore with 12 teeth.
Description of male (ICHUM-5437). Measurements: length of trunk (from chelifore insertion to base of fourth lateral processes) 1.18; width across second lateral processes 2.04; proboscis length 0.52; length of palp articles 2–7: 0.25, 0.15, 0.13, 0.06, 0.07, 0.04; length of oviger articles 1–10 and terminal claw: 0.12, 0.11, 0.13, 0.38, 0.34, 0.18, 0.11, 0.10, 0.04, 0.06, 0.09; length of articles on leg 3 (from coxa 2; including claw): 0.53, 0.28, 1.26, 1.18, 1.23, 0.45, 0.64, 0.40.
Trunk ( Fig. 1A–C View Fig ) with indistinct segment boundaries; covered with many tiny papillae. Lateral processes long, well-spaced, each with long, tapering, dorsodistal tubercle ( Fig. 1B View Fig arrow) and many tiny, unbranched lateral outgrowths each bearing distal spinules ( Fig. 1A View Fig arrow; Fig. 1C View Fig ); tubercle length twice as long as diameter of widest portion of lateral process. Ocular tubercle ( Fig. 1D View Fig ) tall, erect, with pair of tiny tubercles at tip. Eyes absent. Proboscis short, tapering distally. Abdomen long, erect, with few setae.
Chelifore ( Fig. 1B, E View Fig ) scape uniarticulate, with dorsodistal setae. Chela palm ( Fig. 1E View Fig ) with dorsal setae. Finger curved, with 12 teeth.
Palp ( Fig. 1F View Fig ) 7-articulate. Article 2 with distal seta and outer swelling ( Fig. 1F View Fig arrow), articles 4–7 with ventral setae.
Oviger ( Fig. 1G View Fig ) with 10 articles and terminal claw. Articles 1–3 with few setae, article 5 with proximal reversed spine ( Fig. 1G View Fig arrow). Articles 7–10 of left oviger with compound spines in formula 4: 3: 1: 1 (right oviger damaged during dissection).
Legs ( Fig. 1H View Fig ) slender, with dorsal and ventral setae (more setae on ventral side); femur without cement gland; propodus without heel spines or auxiliary claws. Genital pore present on coxa 2 of leg 4.
Description of female (ICHUM-5438). Measurements: length of trunk (from chelifore insertion to base of fourth lateral processes) 1.10; width across second lateral processes 1.67; proboscis length 0.44; length of palp articles 1–7: 0.07, 0.24, 0.15, 0.11, 0.06, 0.04, 0.04; length of oviger articles 1–10 and terminal claw: 0.06, 0.12, 0.30, 0.36, 0.30, 0.15, 0.12, 0.09, 0.05, 0.06, 0.13; length of articles on leg 3 (from coxa 1; including claw): 0.34, 0.45, 0.28, 1.14, 1.06, 1.09, 0.39, 0.61, 0.35.
Trunk ( Fig. 2A, B View Fig ) with indistinct segment boundaries; covered with many tiny papillae. Lateral processes long, well-spaced, each with long, tapering, dorsodistal tubercle ( Fig. 2B View Fig arrow) and several tiny, unbranched lateral outgrowths each bearing distal spinules ( Fig. 2A View Fig arrow); tubercle length less than twice diameter of widest portion of lateral process. Ocular tubercle ( Fig. 2C View Fig ) tall, erect, with pair of tiny tubercles at tip. Eyes absent. Proboscis short, tapering distally. Abdomen long, erect, with few setae.
Chelifore ( Fig. 2B, D View Fig ) scape uniarticulate, with dorsodistal setae. Chela palm ( Fig. 2D View Fig ) with dorsal setae. Finger curved, with 12 teeth.
Palp ( Fig. 2E View Fig ) 7-articulate. Article 2 with distal seta and outer swelling ( Fig. 2E View Fig arrow), articles 4–7 with ventral setae.
Oviger ( Fig. 2F View Fig ) with 10 articles and terminal claw. Articles 1–3 with few setae. Articles 7–10 with compound spines in formula 4: 3: 1: 1 (right), 3: 3: 1: 1 (left).
Legs ( Fig. 2G View Fig ) slender, with dorsal and ventral setae (more setae on ventral side); femur without cement gland; propodus without heel spines or auxiliary claws. Genital pores present on coxa 2 of all legs.
Sexual dimorphism and individual variation. Compared to males, females have fewer tiny lateral outgrowths, a shorter ocular tubercle, shorter dorsodistal tubercles on the lateral processes, shorter oviger articles 4 and 5, a longer terminal claw relative to oviger article 10 (1.12–1.30 in males; 1.72–1.87 in females), a thicker femur, and fewer genital pores (on leg 4 in males, legs 1–4 in females). Females lack the proximal reversed spine on oviger article 5.
The following character varied among specimens: the number of compound spines on oviger articles 7–10 showed in the formula was 4: 3: 1: 1 (left in ICHUM-5437; right in ICHUM-5435), 3: 3: 1:1 (left in ICHUM-5435), or 3: 2:1: 1 (both in ICHUM-5436 and -5438).
Remarks. Although our male specimens shared almost all characters with the holotype, they differed from the male individual in Wang et al. (2015) in the number of compound spines on oviger articles 7–10 (4: 3: 1: 1 or 3: 2:1: 1 versus 3: 2: 1: 1) and the length ratio of the terminal claw to article 10 in the oviger (1.12–1.30 versus 1.0). Furthermore, the holotype has genital pores on legs 3 and 4, whereas we observed them on leg 4 only. Male genital pores have been observed on legs 1–4 in H. longiunguis ( Staples 1982) , thus differing in number and position from H. nanhaiensis from both localities. This raises the question whether, if the number and position of male (and female) genital pores are important characters in species discrimination in this genus, our specimens are indeed conspecific with Wang’s et al. (2015) specimen. To confirm conspecificity, more specimens from both localities and molecular genetic data will be needed.
Wang et al. (2015) measured the width across the second lateral processes of the holotype as 3.49 mm, which he noted was distinctly larger in body size than its congeners. Our specimens were markedly smaller than Wang’s, 1.90– 2.04 mm in males and 1.45–1.67 mm in females. However, based on the 1 mm scale bar accompanying Wang’s fig. 1B, the comparable measurement of the holotype is only about 1.85 mm, which is close to the range in our specimens, indicating an error in the original description. In any case, the other two congeners are smaller in size than H. nanhaiensis from either locality; the width across second lateral processes is 0.92–1.00 mm in male H. micrasterias ( Stock 1954, 1985), and 1.03 mm and 0.87 mm in male and female H. longiunguis , respectively ( Staples 1982).
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