Murphydoris cobbi

Species Profile
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Murphydoris cobbi
Author: Paz-Sedano, Smirnoff, Candas, Gosliner & Pola, 2022
Order: Nudibranchia Family: Goniodorididae
Maximum Size: 6 mm
Sightings: Sunshine Coast, Capricorn/Bunker GBR, Whitsundays
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Previously known on this website as Goniodoridella sp. 01. Changed March, 2022. That original identification was conferred by Dr Richard Willan and later confirmed by Dr Bill Rudman (Sea Slug Forum). Recent molecular and morphological research has provided clarity.
Refer to: Paz-Sedano, S., Smirnoff, D., Candas, M., Gosliner, T. M. & Pola, M., (2022). Rediscovering the overlooked genus Murphydoris (Nudibranchia: Goniodorididae): the first phylogeny and addition of four new species. Zoological Journal of the Linnean Society, 2022, XX, 1–20
For an unbiased and inclusive account of its first sighting in Australia on Saturday, January 8th 2005 refer to the Sea Slug Forum message: http://www.seaslugforum.net/find/22015 – by David Mullins
Here is an extract: “The first specimen was virtually tripped over just as we were about to stand up while exiting from a 2 hour very shallow (max 2 m) shore dive at “The Ledges” off Mooloolaba Beach. A second specimen was found in the same area almost 12 months later and subsequently also at Mudjimba Island off Maroochydore. I remember that first time very well because due to the very poor viz we clipped ourselves together with what we call the “dog leash” in order to keep in touch. Our faces were no more that 6 inches off the substrate the whole time.”
Subsequently, once I started diving/searching/recording the sea slug life in the Mooloolah River commencing March 8th 2014, with Terry Farr and Julie Schubert, this species was sighted on the first dive and almost every dive thereafter and usually in “large” numbers (compared to the count of most sea slug species).
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Murphydoris is a genus of Goniodorididae.
The genus was erected in 1991 at the time of the single species description of Murphydoris singaporensis. Apart from Swennen & Buatip, 2012 further research on the genus has been lacking until Paz-Sedano et al, 2021 undertook a review of the morphological characteristics of the Gonidorididae family followed by Paz-Sedano et al, 2022 who described four new species of Murphydoris. All four of those new species, or at least considered variations thereof, have been recorded by us on the Sunshine Coast, Queensland, Australia. At the time of original recording those four were placed as undescribed species in the Goniodoridella genus due to (what are now viewed as) superficial similarities.
To summarise the external features – Murphydoris shares non-lamellate rhinophores with Goniodoridella, but is unique among goniodorids in lacking peri-anal ctenidia or gills. That means it does not have true gills around the anus. Instead it has some appendages at the termination of the mantle notal edge on each side. These may be homologous to, or at least perform like, true gills, and acting as such are not classed as papillae. Murphydoris lacks lateral and dorsal papillae.
It is these three characteristics – smooth rhinophores, a lack of lateral and dorsal papillae, and lack of peri-anal gills, that help to separate Murphydoris from the other genera of the Goniodorididae family.
David A. Mullins – March 2022
References:
– Baba, K. (1960). The genera Okenia, Goniodoridella and Goniodoris from Japan (Nudibranchia-Goniodorididae). Publications of the Seto Marine Biological Laboratory, 8(1), 79–83.
– Sigurdsson, J. B. (1991). A nudibranch, Murphydoris singaporensis, new genus and species, from Singapore mangroves (Mollusca: Opisthobranchia: Goniodorididae). Raffles Bulletin of Zoology, 39, 259–263.
– Swennen, C., & Buatip, S. (2012). Murphydoris singaporensis (Gastropoda: Nudibranchia: Goniodorididae) found in Thailand; with external and first internal description of the specimens. Strombus, 19(1–2), 9–14.
– Paz-Sedano, S., Díaz-Agras, G., Gosliner, T. M. & Pola, M. (Online 2021). Revealing morphological characteristics of Goniodorididae genera (Mollusca: Nudibranchia). Organisms Biodiversity and Evolutionary Research. (2022) 22:93–116.
– Paz-Sedano, S., Smirnoff, D., Candas, M., Gosliner, T. M. & Pola, M., (2022). Rediscovering the overlooked genus Murphydoris (Nudibranchia: Goniodorididae): the first phylogeny and addition of four new species. Zoological Journal of the Linnean Society, 2022, XX, 1–20
Above: The small Murphydoris cobbi ploughing through the grains of silt on the bed of the Mooloolah River searching for food.