Dendronotus iris Cooper 1863
Creators: name: Korshunova, Tatiana
name: Bakken, Torkild
name: GrØtan, Viktor V.
name: Johnson, Kjetil B.
name: Lundin, Kennet
name: Martynov, Alexander
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Nudibranchia
Dendronotidae
Dendronotus
Dendronotus iris

description: Dendronotus iris Cooper, 1863
Fig. 7
Dendronotus iris Cooper, 1863: 59; MacFarland, 1966: 257–265, Pl. 47, Figs 12– 18; Plate 48, Figs 1–6; Pl. 49, Fig. 4; Pl. 50, Fig. 1; Pl. 51, Figs 1–5; Robilliard, 1970: 446–450, Figs 4–6, 10–12, Pl. 63, Fig. 30; Behrens, 1980: 74; Behrens & Hermosillo, 2005: 94.
Dendronotus giganteus O’Donoghue, 1921: 187–190; Pl. 4, Fig. 47; Pl. 5, Figs 57–59.
Extended diagnosis. Body relatively narrow. Four to eight pairs of branched dorsolateral appendages. Two to four oral veil appendages. Two to five appendages (longest internal) of rhinophoral stalks. Lateral papilla of rhinophoral sheaths present. Rhinophoreswith 15–31 lamellae. 20–40 lip papillae. Basal colour grayish to reddish-orange, with white line bordered foot edge. Dorsal processes of jaws inclined posteriorly at approximately 40° to the longitudinal axis of the jaw body and 0.35 of its length. Masticatory processes bear denticles (possibly including ridge-like structures and denticles). Radula with up to 61 rows of teeth. Central tooth quite narrow, with deep furrows and with up to 18 distinct denticles. Up to 21 lateral teeth commonly smooth, occasionally with up to eight denticles. Ampulla relatively narrow with numerous loops. Bursa copulatrix moderate in size, oval, bent. Seminal receptaculum small, placed distally at a moderately short distance from the vaginal opening. Prostate very long, non-discoid, linear, with numerous alveolar glands. The vas deferens is short, penis moderately short, straight, with blunt tip. Body length of live specimens may reach more than 20 cm.
Distribution. NE Pacific, from southern Alaska to California (but records from Baja California need to be confirmed). As an adult it feeds on cerianthid anthozoans (Wobber, 1970; Shaw, 1991), quite different to other Dendronotus species.
Bathymetry. 10–30 mdepth.
Remarks. This species is clearly distinguished by a combination of external characters (uniform grayish to reddish-orange colour, massive dorsal appendages) and internal characters (linear instead of discoid prostate – unique for the genus), and also by adult behavioral patterns (special “rearing attack” feeding on species of Ceriantharia, e.g., Shaw, 1991). Dendronotusnanus Marcus et Marcus, 1967 was considered a synonym of D. iris (Stout et al., 2010), but in the absence of molecular data and presence of morphological differences (see below) we prefer to retain D. nanus as a separate species (see details below). Dendronotusiris possibly is the largest species of its genus.
description: Published as part of Korshunova, Tatiana, Bakken, Torkild, GrØtan, Viktor V., Johnson, Kjetil B., Lundin, Kennet & Martynov, Alexander, 2021, A synoptic review of the family Dendronotidae (Mollusca: Nudibranchia): a multilevel organismal diversity approach, pp. 93-153 in Contributions to Zoology 90 (1) on pages 121-122, DOI: 10.1163/18759866-BJA10014, http://zenodo.org/record/4623915