Bregmaceros cf. mcclellandi Thompson 1840

Van Hinsbergh, Victor W. M. & Helwerda, Renate A., 2019, Fish Otoliths from the Cabarruyan Piacenzian-Gelasian fauna found in the Philippines, Zootaxa 4563 (3), pp. 401-443 : 420-421

Bregmaceros cf. mcclellandi Thompson 1840

(Figures 61–64)

1995 Bregmaceros macclellandi Smale MJ, Watson G, Hecht T, p. 57, plate 28, fig. D1

1999 Bregmaceros macclellandi Rivaton J, Bourret P, (1999) , pp. 278–279, pl.130, fig. 9–17

Material: 16 specimens in total. Anda1 (3) RGM 962217; Anda2 (2) RGM 962218 ; Anda3 (3) RGM 962219 ; Anda5 (1) RGM 962220 ; AndaCliff1 (1) RGM 962221 ; Roxas (3) RGM 962222 , RGM 962223 , RGM 962224 ; Tiep1 (1) RGM 962225 ; Tiep2 (2) RGM 962226 .

Four specimens are depicted, which have the typical shape of genus Bregmaceros . The largest specimen (2.1 mm length; OL:OH=0.93) (Figure 63) has a broad shallow predorsal lobe, which is rather flat at its top and a separated small but bluntly pointed postdorsal lobe. Along the ventral rim three angles are found. The middle one lies slightly to anterior of the middle of the otolith and is blunt, the postventral forms a prominent roundly pointed extension, while the preventral angle also forms a blunt point in this specimen. The inner surface a slightly convex, except for the predorsal lobe part. The sulcus has a wide ostium and cauda, which are separated by a collum. Below the collum is a round to bean-formed depression, which extends till midway in the direction of the midventral angle.

Three smaller specimens (length 1.51–1.75 mm; OL:OH 1.01–1.07) display a similar general morphology, but the flat predorsal lobe inclines towards the anterior side, by which the anterior rim displays a depression at the dorsal side of the excisura. Furthermore, the preventral part has no angle but—in particular in the smallest specimens—has a rounded shape; the midventral angle is more centrally localized. The shape of the sulcus, general shape of the predorsal lobe, the depression below the collum, and clear postventral pointed extension are comparable to the larger specimen. Similar characteristics were observed in a juvenile specimen of Bregmaceros mcclellandi depicted by Rivaton & Bouttet (1999) (pl. 130 fig. 9–10). According to these authors, B. mcclellandi otoliths can reach a size of 3.4 mm, while many other species usually reach 1.5 mm ( Schwarzhans, 2013c).

Recent otoliths have been published of Bregmaceros atlanticus Goode & Bean, 1886 , B. bathymaster Jordan & Bollmann 1890, B. cantori Milliken & Houde, 1984 , B. japonica Tanaka, 1908 , B. lanceolatu s Shen, 1960, B. mcclellandi and B. nectabanus Whitley, 1941 (Smale etal., 1995; Rivaton & Bourret, 1999; Schwarzhans, 2013c; Lin etal., 1992). Our specimens fit well with small specimens of B. mcclellandi . As several Bregmaceros species are known from the Western Pacific region, among which B. pseudonectabanus Torii, Javonillo & Ozawa, 2004 , of which the otolith characteristics are not yet known, we can only made a provisional identification as Bregmaceros cf. mcclellandi .