Konarus crassicornis ( Stebbing, 1905 )

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 : 34-35

Konarus crassicornis ( Stebbing, 1905)

( Figs. 17A–D )

Heterotanais crassicornis Stebbing, 1905: 4–5 , pl. IA.

Pseudoleptochelia crassicornis Sieg, 1983: 488–489 .

Konarus crassicornis Bamber, 2008c: 184 . Bamber & Chatterjee, 2010: 18–22 , figs. 1–2.

Material examined. Station SG86: 38 specimens, including 9 that are incomplete (HAN-EXP-00.0-TAN03, HAN-EXP-00.0-TAN04, HAN-EXP-00.0-TAN06); 1 male, 23 adults, 9 mancae (HAN-EXP-02.5-TAN04, HAN- EXP-02.5-TAN05, HAN-EXP-02.5-TAN07); 1 male, 22 adults, 1 manca (HAN-EXP-05.0-TAN02, HAN-EXP-05.0-TAN03, HAN-EXP-05.0-TAN06); 36 specimens, including 10 adults and 1 manca (HAN-EXP-07.5-TAN01, HAN-EXP-07.5-TAN02, HAN-EXP-07.5-TAN04, HAN-EXP-07.5-TAN05, HAN-EXP-07.5-TAN06); 1 male, 4 adults, 2 mancae (HAN-EXP-10.0-TAN02, HAN-EXP-10.0-TAN04, HAN-EXP-10.0-TAN05, HAN-EXP-10.0- TAN06). Station SG91: 3 adults (SEN-PRO-00.0-TAN07); 11 adults, 2 mancae (SEN-PRO-02.5-TAN05, SEN- PRO-02.5-TAN09); 1 adult (SEN-PRO-05.0-TAN09); 2 adults (SEN-PRO-07.5-TAN08).

Remarks. Bamber (2006) erected the genus Konarus and designated K. cheiris Bamber, 2006 as its type species. The distinctive feature of this genus is the fat antennule peduncle ( Bamber 2006). Konarus is currently represented by three species ( Anderson 2023), namely K. crassicornis ( Stebbing, 1905) , K. cheiris and K. straddi ( Bamber, 2008c) , which were recorded from intertidal and shallow subtidal (10–40 m) habitats in the Indo-West Pacific including India, Australia (Queensland) and New Caledonia ( Stebbing 1905; Bamber 2006, 2008c; Bamber & Chatterjee 2010). All three species are very similar in general morphology ( Bamber & Chatterjee 2010; Bamber 2013a). The present material from Singapore is most similar to K. crassicornis . Even though males of K. crassicornis from the type locality remain unknown, the male specimens of K. crassicornis in this study can be easily distinguished from the males of K. cheiris and K. straddi based on their chelipeds: (1) propodus ovoid, with mid-ventral triangular apophysis and with adjacent row of one long seta and numerous short setae; (2) fixed finger absent ( Fig. 17D ); and (3) movable finger shorter than propodus. Previous records of K. crassicornis occurred in the intertidal shores of India at Gulf of Mannar, Laccadive Sea ( Stebbing 1905) and the Andaman Islands, Andaman Sea ( Bamber & Chatterjee 2010). In Singaporean waters, this species was found only from intertidal macroalgal turfs in the Singapore Strait, on an exposed seawall at Pulau Hantu and on a sheltered seawall at Sentosa (Pulau Blakang Mati).

Figures

FIGURE 17. Konarus crassicornis (Stebbing, 1905), Singapore: (A) non-ovigerous female, SEN-PRO-00.0-TAN07, dorsal habitus, with inset showing 'fat' peduncle antennule article-1 (arrow); (B) non-ovigerous female, SEN-PRO-02.5-TAN05, lateral habitus; (C) adult male, SEN-PRO-07.5-TAN08, dorsal habitus; (D) adult male, SEN-PRO-05.0- TAN09, lateral habitus, with inset showing the reduced chela fixed finger (arrow). Scale bar = 1 mm.