Chondrochelia sp.

Kong, Chim Chee, 2024, A synopsis of the Tanaidacea (Crustacea: Peracarida) of Singapore, with a review of tanaidacean diversity in Southeast Asia and the South China Sea, Zootaxa 5451 (1), pp. 1-75 : 35-37

Chondrochelia sp. SG#1

( Figs. 18A–E )

Material examined. Station SG 1: 4 specimens. Station SG 2: 3 females. Station SG 3: 2 females. Station SG 10: 17 damaged specimens (278). Station SG 11: 80 damaged specimens (021). Station SG 12: 11 damaged specimens (016), H06-2, Punggol?. Station SG 20: 10 specimens. Station SG 22: 1 specimen (CR1115-P02-02-02), 2 November 2015. Station SG 26: 2 specimens (CR1115-PS06-02-01) and 1 specimen (CR1115-PS06-03-02), 5 November 2015; 1 specimen (CR0516-PS06-01-02), 1 specimen (CR0516-PS06-02-02) and 2 specimens (CR0516-PS06-03-02), 12 May 2016; 1 male (CR1016-PS06-02), 3 October 2016; 2 specimens (CR0517-PS06-02-01), 15 May 2017. Station SG 32: 1 female (No. 41066). Station SG 35: 1 specimen (JS-6065). Station SG 41: 1 female ( RF 10-055). Station SG 45: 3 females (SS-3481, SS-6790). Station SG 46: 10 females and 3 males (SS-6291). Station SG 48: 3 females (SEA-1156, SEA-1369). Station SG 53: 1 female (INT-0851). Station SG 56: 1 specimen (SEA-7725). Station SG 60: 1 female and 1 male (INT-1175). Station SG 61: 3 females (INT-1223). Station SG 64: 1 male (ARM-0885). Station SG 73: 1 specimen (SUB-1481). Station SG 80: 2 females (TR-0050). Station SG 81: 1 female (TR-0127). Station SG 86: 11 specimens, including 7 mancae (HAN-EXP-00.0-TAN05, HAN-EXP-00.0-TAN07); 10 adults, 14 mancae (HAN-EXP-02.5-TAN01, HAN-EXP-02.5-TAN02, HAN-EXP-02.5-TAN03); 1 adult, 4 mancae (HAN- EXP-05.0-TAN04, HAN-EXP-05.0-TAN08); 1 incomplete adult (HAN-EXP-07.5-TAN03); 4 adults (HAN-EXP-10.0-TAN07, HAN-EXP-10.0-TAN08, HAN-EXP-10.0-TAN09, HAN-EXP-10.0-TAN10). Station SG 87: 2 males, 4 non-ovigerous females (HAN-PRO-00.0-TAN01, HAN-PRO-00.0-TAN02, HAN-PRO-00.0-TAN03, HAN- PRO-00.0-TAN04, HAN-PRO-00.0-TAN05, HAN-PRO-00.0-TAN06); 1 female (HAN-PRO-02.5-TAN01) and 1 manca-II (HAN-PRO-02.5-TAN02); 1 manca-III (HAN-PRO-05.0-TAN01); 2 non-ovigerous females, 1 mancaII (HAN-PRO-10.0-TAN01, HAN-PRO-10.0-TAN02, HAN-PRO-10.0-TAN03). Station SG 88: 2 non-ovigerous females (LAZ-EXP-00.0-TAN02); 1 ovigerous female (LAZ-EXP-02.5-TAN06); 2 adults, 1 manca (LAZ-PRO-00.0-TAN01); 2 adults, 2 mancae (LAZ-PRO-02.5-TAN01); 4 ovigerous females, 22 non-ovigerous females, 7 mancae (LAZ-PRO-05.0-TAN01, LAZ-PRO-05.0-TAN02, LAZ-PRO-05.0-TAN03); 3 males, 2 ovigerous females, 4 females with brood pouch, 32 non-ovigerous females, 5 mancae III, 18 mancae II (LAZ-PRO-07.5-TAN01, LAZ-PRO-07.5-TAN02, LAZ-PRO-07.5-TAN03, LAZ-PRO-07.5-TAN04, LAZ-PRO-07.5-TAN05, LAZ-PRO-07.5-TAN06, LAZ-PRO-07.5-TAN07, LAZ-PRO-07.5-TAN08); 3 males, 1 female with brood pouch, 40 non-ovigerous females, 25 mancae III, 33 mancae II, 10 incomplete specimens (LAZ-PRO-10.0-TAN01, LAZ-PRO-10.0-TAN02, LAZ-PRO-10.0-TAN03, LAZ-PRO-10.0-TAN04, LAZ-PRO-10.0-TAN05, LAZ-PRO-10.0-TAN06, LAZ-PRO-10.0-TAN07). Station SG 90: 1 ovigerous female, 10 non-ovigerous females, 2 mancae (SEN-EXP-02.5-TAN07, SEN-EXP-02.5-TAN08); 18 adults, 5 mancae (SEN-EXP-05.0-TAN09, SEN-EXP-05.0-TAN10); 22 non-ovigerous females, 42 mancae (SEN-EXP-07.5-TAN07, SEN-EXP-07.5-TAN08, SEN-EXP-07.5-TAN09); 1 male, 7 non-ovigerous females (SEN-EXP-10.0-TAN08, SEN-EXP-10.0-TAN09). Station SG 91: 4 adults (SEN- PRO-00.0-TAN06); 1 non-ovigerous female, 1 manca (SEN-PRO-02.5-TAN06, SEN-PRO-02.5-TAN07); 1 male, 16 non-ovigerous female, 3 mancae (SEN-PRO-05.0-TAN05, SEN-PRO-05.0-TAN06, SEN-PRO-05.0-TAN07) ;

87 specimens including 1 male, 52 non-ovigerous females (SEN-PRO-07.5-TAN05, SEN-PRO-07.5-TAN06, SEN-PRO-07.5-TAN07); 2 males, 4 ovigerous females, 18 non-ovigerous females, 3 mancae III, 4 mancae II, 8 incomplete specimens (SEN-PRO-10.0-TAN01, SEN-PRO-10.0-TAN02, SEN-PRO-10.0-TAN03, SEN-PRO-10.0-TAN04, SEN-PRO-10.0-TAN05, SEN-PRO-10.0-TAN06, SEN-PRO-10.0-TAN07).

Remarks. Guţu (2016) erected the genus Chondrochelia to accommodate 21 species from the ‘group Leptochelia dubia ’ based on the thickness of the male chela. He also designated Chondrochelia distincta Guţu, 2016 from Indonesia as the type species of the genus. Bird (2019, 2020) found the definition of Chondrochelia females problematic, although several characters may be diagnostic when used as a combination, and suggested that the diagnostic characters of this genus have yet to be properly resolved. Chondrochelia is currently represented by 30 species ( Anderson 2023) but identification keys are available only for selected species in the Indo-Pacific ( Guţu 2016; Bird 2019) even though this genus is widely distributed from the intertidal to shallow subtidal (up to 215 m depth but usually much shallower) habitats in the Atlantic, Indian, Pacific and Southern Oceans ( Jarquín-González et al. 2015; Bird 2019; Jarquín-González & Carrera-Parra 2022).

The present material from Singapore cannot be identified using these keys. When compared with other known species, these Singaporean specimens were found to be most similar to C. caribensis Jarquín-González & Carrera-Parra, 2022 from the Caribbean Sea based on the males having (1) 10–11 articles on the antennule flagellum; (2) one proximal and one distal teeth on the chela fixed finger; (3) 5–6 articles on the uropod endopod and two articles on the exopod; and (4) uropod exopod about 0.8–0.9 times as long as endopod article-1. The long distance between Singapore and the Caribbean Sea suggests that tanaids from these two localities are unlikely to belong to the same species. Due to this reason, Chondrochelia sp. SG#1 is a potentially undescribed species. Chondrochelia sp. SG#1 was collected from many stations in Singaporean waters, but was glaringly absent from the inner West and East Johor Straits. This otherwise widespread species was found from mid-intertidal (0.1–1.0 m above chart datum) to shallow subtidal (5–16 m depth) habitats, usually amongst macroalgae on hard surfaces (e.g., gravel, rocks, wood, corals, and bivalves).

Genus Leptochelia Dana, 1849

Figures

FIGURE 18. Chondrochelia sp. SG#1, Singapore: (A, B) non-ovigerous female, INT-1175, dorsal and lateral habitus, respectively; (C) female with brood pouch, TR0050, lateral habitus; (D, E) adult male, INT-1175, dorsal and lateral habitus, respectively. Scale bar = 1 mm.