Dendronotus kamchaticus Ekimova et al., 2015

Korshunova, Tatiana, Sanamyan, Nadezhda, Zimina, Olga, Fletcher, Karin & Martynov, Alexander, 2016, Two new species and a remarkable record of the genus Dendronotus from the North Pacific and Arctic oceans (Nudibranchia), ZooKeys 630, pp. 19-42 : 27-29

Taxon classification Animalia Nudibranchia Dendronotidae

Dendronotus kamchaticus Ekimova et al., 2015

Dendronotus kamchaticus Ekimova, Korshunova, Schepetov, Neretina, Sanamyan & Martynov, 2015: 869-872, figs 6E, 8D, 16A, B, 17, 18A.

Material.

1 specimen, ZMMU Op-565, NE Pacific, Puget Sound, Rich Passage, Washington State, USA, 47 °58.7' N– 122°54.65'W, 17.03.2014, depth 17.4 m, stones and algae, SCUBA diving, collector Karin Fletcher.

Description.

Body elongate, 30 mm in length (live specimen, Fig. 4C). Four branched appendages of oral veil, ca. five appendages of rhinophoral stalks, approximately ten rhinophoral lamellae, branched rhinophoral lateral papilla present, six pairs dorsolateral appendages, ca. 10-15 lip papillae. Dorsolateral appendages with long primary stalk and secondary branches, and elongate tertiary branches (Fig. 4C). Reproductive and anal openings placed laterally on right side. General colour pale, translucent white with few scattered brown dots and opaque white stripe on dorsal appendages (Fig. 4C).

Dorsal processes of jaws inclined posteriorly at approximately 70° to longitudinal axis of jaw body and 0.37 of its length. Masticatory borders with fine denticles. Radula formula 44 × 3 –10.1.10– 3. Central tooth with reduced or completely absent denticles and furrows in posterior rows (Fig. 4D); anteriormost juvenile rows denticulated. Lateral teeth short, slightly curved, bearing up to six distinct denticles.

Reproductive system triaulic. Ampulla wide, folded twice. Prostate consists of approximately 20-25 alveolar glands. Vas deferens relatively short and expands to oval penial sheath and conical penis. Vagina moderate in length. Bursa copulatrix large, rounded, elongated, with small seminal receptaculum placed distally.

Biology.

Inhabits stony and rocky substrates.

Distribution.

According to the present data Dendronotus kamchaticus has a broad transpacific distribution in the northern part of the Pacific Ocean.

Remarks.

Dendronotus kamchaticus was recently described from Kamchatka in the Russian NW Pacific ( Ekimova et al. 2015). Here an outstanding and unexpected record of Dendronotus kamchaticus is presented from the American NE Pacific (Washington state). The single collected specimen matches closely with Dendronotus kamchaticus from the type locality, and genetic distances between the four Dendronotus kamchaticus , including Dendronotus kamchaticus from Washington waters, range from 0-1.1% for COI, and 0-0.2% for 16S. Mean p-distance value of the COI marker within Dendronotus kamchaticus group is 0.7%. Furthermore, Dendronotus kamchaticus from Washington waters share an important diagnostic character with those from the type locality, the central teeth with strongly reduced denticles and furrows in the posterior radular teeth (Fig. 4D) and denticulated anteriormost juvenile rows. This is the first record of Dendronotus kamchaticus from the NE Pacific, approximately 6000 km away from the type locality, across the ocean.