Nanuca trainitoi

Nanuca trainitoi (Furfaro & Mariottini, 2020)

Synonyms

• Dondice trainitoi Furfaro & Mariottini, 2020 (original)

Description
The body is small (8-15mm), but slender and elongated, coloured translucent cream with bright white spots along the border of the foot, oral foot corners and tail. A characteristic iridescent light blue band runs along the dorsum, backwards to the tail and forward to the head where it bifurcates until the half part of the oral tentacles. Two lateral lines of the same color are present on the dorsum, running from the sides of the head below the rhinophores, to the tail where they join the median line, while becoming narrower and lighter along the body. Rhinophores are basally smooth with 6-17 (usually 10-12) dish shaped lamellae on the distal end, with a cylindrical tip. There is a bright white/yellowish stripe in the distal end, wider anteriorly as in cerata. On the head, characteristic black jaws are visible by transparency. Eyes located at the base of the rhinophores. Oral tentacles are longer than the rhinophores, cylindrical and elongated with a bright band of the same white/yellowish of the rhinophores. Cerata are slender and cylindrical, coloured translucent cream with a yellowish digestive gland inside that turns increasingly orange towards the tip. The distal part of the cerata has a bright yellowish ring, larger in the anterior part than in the back. There are 4-5 clusters of two rows of cerata each, except the last group that only has one row. The first group has 22-24 cerata and is located ahead of the precardiac area, the two median groups have 16-18 and 14-18 cerata respectively, and the last group has a single row of 5-6 cerata. The foot is narrow with a bilabiate anterior part that extends into two well-defined propodial tentacles.

Biology
Most of the specimens found so far were living over two nearby shipwrecks covered of torn trawling nets, feeding on hydroid colonies covering these nets. The rest were found on hydroid colonies on a coralligenous rocky bottom. All findings have been from late May to early September, at depths rounding 30 m of water. It has been observed that N.trainitoi can autotomize its cerata when disturbed, something that similar species like N.banyulensis can not do. Due to its recent description, little else is known of this species.

Etymology

• Trainitoi. Named after Egidio Trainito, expert in nudibranch biology and Mediterranean marine
  biodiversity, underwater photographer and good friend of the authors.

Distribution
Since its recent description this species was only known from the Italian coast: off Civitavecchia (the type locality), Portofino MPA and the island of Procida (Naples), and also from the West coast of Crete (Greece). In november 2020 it was also reported from Malta, on the M/V Rozi wreck (Kristaps Dzonsons, pers.comm.). Due to its similarities, reports of juvenile Nemesignis banyulensis should be revised, particularly black jaws are a distinctive trait for N.trainitoi, while N.banyulensis has reddish jaws, both easily viewed by transparency on the head.

Known georeferenced records of the species: Nanuca trainitoi
Sources:
: OBIS : GROC 2010-2011 : Enric Madrenas : João Pedro Silva : Bernard Picton : GBIF.ORG	: OPK : VIMAR : Manuel Ballesteros. : M@re Nostrum : Altres fonts : Marine Regions

Abundance

Western Mediterranean:	★☆☆☆☆
Eastern Mediterranean:	☆☆☆☆☆
Atlantic Ocean:	☆☆☆☆☆