Propallene, Schimkewitsch, 1909

Wang, Jianjia, Lin, Heshan, Huang, Dingyong, Zheng, Xinqing, Liu, Qinghe, Wang, Jianjun, Niu, Wentao & Zhang, Feng, 2020, Recent collections of sea spiders (Arthropoda: Pycnogonida) from China seas, with some new records and a checklist of the area, Zootaxa 4802 (2), pp. 361-373 : 364

Propallene sp.

( Fig. 2 a–g)

Material examined Female (TIO2016 CNHD3101 ), Cangnan, Zhejiang, China, 27.16°N 120.49°E, 15.5 m depth, 15 Nov. 2016, Kun Liu & Jianfeng Mou .

Description Trunk fully segmented, smooth ( Fig. 2-a ). Lateral processes glabrous, separated by less than their own diameter. Ocular tubercle low, eyes invisible, with two papillae on top. Proboscis short, pointing slightly downward. Abdomen subtriangular, short, downward. Chelifore longer than proboscis, one–articled scape ( Fig. 2-e ). Palm slightly shorter than movable finger but slightly longer than immovable finger, with distally long setae. Both fingers curved, movable and immovable with four and three teeth respective. Without palp. Oviger 10-articled ( Fig. 2-b, c, d ). O4 longest. O5-O9 with one or two distally short setae. Terminal four oviger articles with compound spines, formula 7:7:6:9, distal spines on each article with one or two thick lateral teeth, different from the others with denticulate teeth. Legs slender, with few setae ( Fig. 2-f, g ). Coxa 2 longer than coxa 1 and 3 together. Femora longest, swollen with eggs. First tibiae longer than second tibiae. Tarsus small, subtriangular, with dorsal and ventral setae. Propodus straight with two long simple spines basally and nine sole spines. Main claw strong, about 0.6 propodal length, curved, without auxiliaries. Genital pores round and big, present ventrally on second coxae of all legs.

Measurements (in mm) Trunk length (from chelifore insertion to tip of 4th lateral processes), 1.09; trunk width (across 2nd lateral processes), 0.64; proboscis length, 0.28; abdomen length, 0.11.

Length of oviger articles 1-10 respectively: 0.07; 0.11; 0.13; 0.23; 0.18; 0.11; 0.16; 0.15; 0.13; 0.10.

Third leg, coxa 1, 0.22; coxa 2, 0.41; coxa 3, 0.17; femur, 0.71; tibia 1, 0.57; tibia 2, 0.48; tarsus, 0.05; propodus, 0.40; claw, 0.25.

Remarks According to the diagnosis of Propallene ( Stock, 1975; Staples, 1979), this female specimen was definitely assigned to this genus, but it was not firm to determine the species with lacking of male specimens and limited descriptions about females of other Propallene species.

P. crinipes Stock, 1968 , P. kempi ( Calman, 1923) and females of P. stocki Fage, 1956 shared the common characteristic of less teeth (total number<8) present on chela fingers. We could distinguish our specimen with P. crinipes by compact lateral processes, with P. kempi by compact lateral processes and straight propodus, with females of P. stocki by elongated second coxa, ratio of two tibiae and less sole spines.

Although this female showed several differences between the existing species with full description about both sexes, it was unreliable for establishing a new species relying on a single female specimen, especially in view of distinguishing among species in this genus mainly base on male characters, so we just described and illustrated here and waited for more material especially males.

Huang and Lin (2012a) had listed P. longiceps (Böhm, 1879) in the checklist occurring in China seas, but this species did not appear in Shao et al. (2010). This specimen might be actually the first recorded in China for the genus Propallene .

Figures

FIGURE 2. Propallene sp. (TIO2016CNHD3101) female, a. trunk, dorsal view; b. oviger; c. terminal articles of oviger, enlarged; d. compound spines on terminal articles of oviger, enlarged; e. chela; f. Leg 3; g. tarsus, propodus and claw of leg 3, enlarged; Propallene sp. indet., (TIO908XM2901) Juvenile, h. tarsus, propodus and claw of leg 3, enlarged; Paranymphon spinosum (TIO2016DH0501) male, i. palp, dorsal view. Scale bars a, f=0.5 mm, b, g, i=0.2 mm, c, e, h=0.1 mm.