Madrella sp.

Image courtesy of Jayne Bruner
Photo taken at Cobb's Cliff dive site in Milne Bay, Papua New Guinea.

Madrella sp. undescribed

Our first guess Id'ed this species as a Galeojanolus. See Ali's BOW on the same critter, just a different color, awhile back, and page 320 of Indo-Pacific Nudibranchs.

This interesting small beast belongs to a small family, the Madrellidae which is closely related to the Proctonotidae (classical Janolids) but its members have an oral veil.

Senior author of the NEW - Nudibranchs and Sea Slugs - Indo-Pacific Terry Gosliner has determined that the species actually belongs to the genus Madrella, and will be listed as Madrella sp. 1 in this revised field guide, coming out this fall.

This undescribed species has a transparent brownish body, that is either clear like Jayne's specimen here, or with a network of opaque white on the cerata, which are shaped like bottles or bowling pins. It apparently lacks a carnacle between the rhinophores, found on members of its sister genus, Janolus. Some members of this genus have chemical glands at the base of their cerata that release a noxious substance when disturbed.

This species is known only from Papua New Guinea and may reach 25mm in length. It is found under coral rubble in 7 m, on barrier reefs, where it feed on bryozoans.

Dave Behrens
Sammamish, WA 98074
Feb., 2015
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Jayne and husband Bob were YMCA certified in 1977 in the stone quarries of western Pennsylvania and northern Ohio. In the early '90s they experienced Indonesia and Papua New Guinea for the first time. Their first trip to PNG was on the maiden voyage of the Tiata with Kevin Baldwin.

Bob pursued film stills until 1999 and then switched to video. He "retired" in 2009 to "see more on the reef". Jayne was a non-photographer (land or sea) until 2008 when a fellow diver gave her a point & shoot to try. That launched a passion to capture the world of nudis that has yet to be satisfied. She currently is shooting with an Olympus OM-D E-M1 in a Nauticam housing with an Ikelite 161 strobe.

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