Nomorhamphus megarrhamphus

Kraemer, Janina, Thieme, Philipp, Hadiaty, Renny Kurnia & Herder, Fabian, 2019, Structure of the andropodium of the viviparous halfbeak genus Nomorhamphus (Atherinomorpha: Beloniformes: Zenarchopteridae), endemic to Sulawesi, Indonesia, Raffles Bulletin of Zoology 67, pp. 247-259 : 252

Nomorhamphus megarrhamphus & N. weberi

( Fig. 5 )

Pigmentation. Lack of black pigment at posterior anal fin rays, few and small melanophores at cryptoplica and base of fin rays.

Andropodium. All males investigated are lacking a physa and the cryptoplica is weakly developed, covering only a small basal part of the andropodial fin rays. The anal-fin rays forming the andropodium appear less curved and modified compared to other species. 1 st anal pterygiophore thickened, angled anteriorly. 2 nd fin ray with 9–11 segments proximal to spinae; segments 3–5 broader than all other segments of the 2 nd fin ray. N. megarrhamphus : spiculus clearly segmented at proximal end, short and thin, dorsal portion slightly curved, in contact with distal segments of 3 rd fin ray. N. weberi : sickle-shaped spiculus, not clearly segmented, pointed ventrally, not in contact with tip of 3 rd fin ray. 3 rd fin ray with segments 2/3–6/7 composed of three longitudinal rows, each row approximately 1/3 the height of the respective segment. 4 th fin ray approximately as broad as 2 nd fin ray. N. weberi : segments 3–5 composed of three longitudinal rows, each row approximately 1/3 the height of the respective segment. 5 th fin ray thin, not noticeably thickened.

Figures

Fig. 5. A, B, diagrammatic representation of andropodium of (A) Nomorhamphus megarrhamphus, ZMH 7153, 38.3 mm SL and (B) N. weberi, ZMH 7970, 41.5 mm SL. C, D, rendered image of andropodium of (C) N. megarrhamphus, ZMH 7153, 43.4 mm SL and (D) N. weberi. Scale bar = 1 mm. Bone stippled. Arrowheads point to spiculi of N. megarrhamphus (A) and N. weberi (B) and tips of the third anal-fin ray.