Opisthobranch of the Week is Chromodoris balat

Chromodoris balat
Image courtesy of Constantinos Petrinos
Lembeh Straits, Indonesia
Sept. 2003

Adanara, Flores Island, 15 meters, Indonesia

Chromodoris balat Bonomo & Gosliner, 2020

As promised last week, this week's BOW presents the second of four new species of Chromodoris described by Lynn Bonomo and Terry Gosliner.

Lynn and Terry explain that the name Chromodoris balat comes from the Filipino word for blotch or mark. Since the external morphology has strikingly large blotches across the mantle, they wanted to connote that with the name. The word balat in Filipino also comes with a negative connotation associated with birthmarks and means unlucky or misfortunate.

We misidentified this species as Chromodoris striatella Bergh 1876, back in September of 2003.

Chromodoris bilat is listed as Chromodoris sp. 12 in NSSI 2nd Edition (page 140), among the other thin striped chromodorids.

The living animal is moderately large, with a length around 45 mm. Body is a cream-white color with dark brown broken lines running vertically down the mantle. At several random places along the mantle, large dark brown blotches or spots appear covering the lines. The marginal band includes yellow orange broken spots around the outside with a white inner marginal band. In the white area, there are small orange, yellow, and red spots around the whole nudibranch. The gill branches are red brown and have bright opaque white spots across them. The rhinophores are red brown with bright opaque white spots

Genetic analysis indicated that C. balat is a sister species to Chromodoris lineolata (van Hasselt 1824}(Bill Rudman's Sea Slug Forum). Externally, it differs from C. lineolata in having large brown blotches with areas of white and brown stripes, whereas C. lineolata has solid brown pigment and white lines, without blotches. Chromodoris striatella which we first ID'ed this species as has a single medial blotch. In C. balat the orange marginal band is interrupted whereas it is continuous in both C. lineolata and C. striatella.

This species is only known from Matotonngil Point (Anilao) in the Philippines (the type locality),Lembeh, Indonesia, where it was photographed by Constantinos Petrinos,Flores, Indonesia, and the ""Passage" in Raja Ampat, West Papua

Tune in for the next two weeks to see the remaining two new species.

Reference:

LYNN J. BONOMO & TERRENCE M. GOSLINER. 2020. Adding stars to the Chromodoris (Nudibranchia, Chromodorididae) galaxy with the description of four new species. Zootaxa 4819 (3): 401-435.

Dave Behrens
Sammamish, WA 98074
Dec., 2020
Send Dave email at davidwbehrens@gmail.com

Constantinos Petrinos is a full time professional underwater photographer. He was born in Athens in 1961 and spent his early childhood in Cameroon, Africa. While growing up he aspired to become a marine biologist but more practical considerations led him to business studies. He obtained a Master's in Business Administration from Dartmouth College in the USA. A while ago he decided to free himself from business suits and suffocating ties and dive the world's oceans. His photographs have won awards at many competitions, including the BBC Wildlife Photographer of the Year. His articles and photos have appeared in various magazines, such as BBC Wildlife, Tauchen, Der Spiegel, Duiken, Dive, Oceans Illustrated, Skin Diver, Scuba Diver Australasia and the Greek editions of National Geographic and National Geographic Traveller. He is the photographer on location for the Hellenic Institute of Marine Archaeology, which conducts underwater excavations in conjunction with the Greek Ministry of Culture. Constantinos is the underwater photography expert for the Nikon Owners Club International. Throughout the year, Constantinos conducts slide shows in Greek schools, to promote marine awareness. He is a Fellow of the Royal Photographic Society.

Constantinos prefers to stay on location for a minimum of two months when working on major projects. He believes that you need to spend many hours underwater to familiarise yourself with the particular habitat and the species present in order to be able to capture behavioural scenes on film. For his book, Realm of the Pygmy Seahorse, he spent five months in Sulawesi and took 25,000 slides.

Send Contantinos mail at petrinos@otenet.gr
or visit his Web Site .

4 From left to right, Terry Gosliner, Angel Valdes, Dave Behrens La Jolla, Calif.

Send Dave email at davidwbehrens@gmail.com