Ampharete Malmgren, 1865

Krüger, Lotte, Dietrich, Anna, Bastrop, Ralf & Bick, Andreas, 2022, From synonym to valid species: Redescriptions of Ampharete acutifrons (Grube, 1860) and A. cirrata Webster & Benedict, 1887, and brief descriptions of A. baltica Eliason, 1955 and A. grubei Malmgren, 1865 (Annelida: Terebellida: Ampharetidae), Zootaxa 5174 (4), pp. 357-380 : 360

Ampharete Malmgren, 1865

Type species: Amphicteis acutifrons Grube, 1860

Generic diagnosis (emended after Imajima et al. (2012), and Ebbe & Purschke (2020)). Prostomium with middle lobe delimited by incision, without glandular ridges. Four, or exceptionally three, pairs of cirriform, or exceptionally pinnate, branchiae. Buccal tentacles pinnate/papillose. 14–15 thoracic chaetigers; segments II+ III fused; notochaetae on segment II (=paleae) absent or present, then in varying size from enlarged to regular notochaetae size. 11 or 12 thoracic uncinigers. Notopodial cirri absent. Elevated or modified notopodia absent. Two intermediate segments, i.e., without notopodia but with neuropodial tori (similar to those in thoracic uncinigers). Papillae (glandular pads?) above neuropodia on intermediate and abdominal segments usually present. One pair of dorsal nephridial papillae on segment IV.

Remarks. Segments II + III are fused, but a separation of the segments can be observed ventrally. Paleae are clearly originating from segment II, followed by an achaetous segment III, which can be recognized by the presence of a vestigial notopodium on segment III ( Fig. 4C ). We included the paleae-bearing chaetiger (segment II) into the count of thoracic chaetigers ( Reuscher et al. 2009). As paleae can be absent or present, the number of thoracic chaetigers varies from 14 to 15.

Figures

FIGURE 4. Ampharete cirrata, Micrographs of methyl blue and ShirlastainA staining patterns. A. Complete specimen, lateral view. B. Posterior end with anal cirri and two pinnules with dorsal cirri, lateral view, ventral side on the right. C. Anterior end, lateral view. Arrow is pointing towards vestigial notopodium on segment III. D. Thoracic notopodium with thick and thin chaetae. E. Dissected notopodium, showing differing diameters of chaetae. A, B, D: Methyl blue staining. C, E: ShirlastainA staining. Scale bars: A = 1 mm. B– E = 200 µm.