Trypanobia ( Imajima & Hartman, 1964 )

Aguado, M. Teresa, Murray, Anna & Hutchings, Pat, 2015, Syllidae (Annelida: Phyllodocida) from Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 35-60 : 52

Genus Trypanobia ( Imajima & Hartman, 1964) n. comb.

Trypanosyllis (Trypanobia) Imajima & Hartman, 1964: 128 . Trypanosyllis (Trypanobia) .— San Martín et al. 2010: 42 –43.

Type species. Haplosyllis depressa Augener, 1913 , designated by Imajima & Hartman (1964).

Diagnosis. (After San Martín et al. 2010). Mid- to large-sized body, ribbon-like, strongly dorsoventrally flattened, with numerous short segments. Prostomium with four eyes and three antennae. Palps completely separate, ventrally directed. Two pairs of tentacular cirri. Antennae, tentacular and dorsal cirri distinctly articulated. Pharynx with trepan. Pharyngeal tooth absent. Chaetae all thick, simple; simple capillary chaetae absent.

Remarks. Imajima & Hartman (1964) erected the subgenus Trypanobia within Trypanosyllis to include species with ribbon-shaped bodies but having only simple chaetae. San Martín et al. (2010) maintained this subgenus, though suggested that the differences may be great enough to consider it as an independent genus. Recently, Aguado et al. (2015) performed a phylogenetic analysis whose results show species of Trypanobia ( T. depressa and T. cryptica ) in a monophyletic group, while Trypanosyllis species grouped in other non-sister clades. Herein, we propose Trypanobia as a genus separate from Trypanosyllis , with a geographical distribution restricted to the Pacific Ocean. In addition, Trypanobia has a different kind of stolon to Trypanosyllis . Stolons in Trypanosyllis are acerous or tetraglene (with two pairs of eyes), while in Trypanobia they also have two pairs of eyes, ventrally developed, but there is also a pair of small anterolateral appendages ( Okada 1933; this study). Trypanobia currently includes five species: T. (T.) depressa ( Augener, 1913) from Australia and Japan, T. ankyloseta Day, 1960 from South Africa ( Day 1960), T. (T.) asterobia Okada, 1933 from Japan (Imajima 1966), Trypanobia (T.) foliosa Imajima, 2003 from Japan and Australia (the latter with doubts sensu San Martín et al. 2010), and an additional species described herein, Trypanobia cryptica n. sp. Trypanobia depressa and Trypanobia cryptica n. sp. live in association with bright red sponges. The live specimens have exactly the same colour pattern as their hosts.

Additionally, there are two species, Trypanosyllis inglei Perkins, 1980 and Trypanosyllis sp. ( Çinar 2007) with two kinds of chaetae: simple (where fusion between blade and shaft is apparent), and compound (with shafts and falcigers). Their relationship with Trypanosyllis and Trypanobia needs further phylogenetic study.