Anguilla borneensis Popta, 1924

Lin, Yen-Ting & Han, Yu-San, 2024, Species diversity of freshwater glass eel (Anguilliformes, Anguillidae) of Yilan, Taiwan, with remark on two new records, ZooKeys 1220, pp. 5-14 : 5-14

Anguilla borneensis Popta, 1924

Figs 3 , 4 , Table 3

Material examined.

NTUIFS IL 21’0715-207 , 49.5 mm TL, off the estuary of the Yilan River , Yilan, northeastern Taiwan (24.7162 ° N, 121.8352 ° E), 15 July 2021, fyke net, collected by Yen-Ting Lin .

Short description.

PDL 26.3 % in TL; PAL 36.4 % in TL; fin-difference ratio 10.1 %. Body extremely elongate, head length 10.1 % TL. The specimen was in fresh condition, with black pigment distributed on the caudal peduncle and caudal fin; pigmentation stages V A (Fig. 4 ).

Distribution.

Indonesia ( Watanabe et al. 2014); Taiwan (glass eel only, present study).

Remarks.

The best-matched GenBank accession number for NTUIFS IL 21 ’ 0715-207 was found to be NC _ 006536.1, which corresponds to A. malgumora submitted by Minegishi et al. (2005). However, it is noteworthy that A. malgumora was identified as a junior synonym of A. borneensis by Minegishi et al. (2005). Based on the comprehensive examination by Minegishi et al. (2005) and the detailed description provided in NC _ 006536.1, we can confidently affirm that our specimen NTUIFS IL 21 ’ 0715-207 is A. borneensis . Herein, we report the first record of A. borneensis outside of the Indonesia ( Watanabe et al. 2014).

Figures

Figure 3. Anguilla borneensis (NTUIFS IL 21 ’ 0715-207), 49.5 mm TL. Preserved in 95 % alcohol. Scale bar: 10 mm.

Figure 4. Pigmentation on the tail tip of Anguilla borneensis (NTUIFS IL 21 ’ 0715-207).