View this and other underwater images at Ryan’s Flickr site.
Adam Harding took this image of Dirona albolineatain August of 2010
Domain Eukarya Kingdom Animalia Phylum Mollusca Class Gastropoda Subclass: Heterobranchia Order Nudibranchia Suborder: Cladobranchia Family Dironidae Genus Dirona Species D.albolineata MacFarland and Cockerell & Eliot, 1905) Common Name: Alabaster Nudibranch Other molluscs at Race Rocks
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
Many cryptobranch dorid nudibranchs contain innumerable calcareous spicules, yet the function of these elements is unknown. Two possible roles are defense against predators and structural support. In one dorid, Cadlina luteomarginata, whole‐mount and thin‐section staining revealed an intricate network of spicule tracts and connective tissue ramifying throughout the body, with muscle fibers associated with this spicule/connective tissue matrix and inserting into it. Spicules were present in high concentrations in all areas of the body, but highest in exterior mantle tissue. Relative investment increased isometrically with body size for most body regions, in contrast to the positively allometric investment seen in prosobranch shells. Bioassays with artificial food indicated that spicules alone did not deter generalist crabs and anemones, and only weakly increased the deterrence of secondary chemicals to anemones. Thus, while nudibranch spicules may serve as a defense against other predators, their primary role may be in body support.
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
We had previously called this species D. sandiegensis, but we changed it because of this entry in Wikipedia Describing D.sandiegensis;”This nudibranch grows to about 100 mm (4″) in length. The background color can be white or any shade of yellow to a yellowish brown, and it has characteristic markings consisting of a few brown rings or irregular spots. Specimens with more numerous spots are Diaulula odonoghuei.” Wikipedia
Domain Eukarya Kingdom Animalia Phylum Mollusca Class Gastropoda Superfamily Doridoidea Family Discodorididae Genus Diaulula
Species D.odonoghuei
Common Name: The spotted leopard dorid
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams. Oct 2010 , by Ryan Murphy
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
This image by Ryan Murphy is rather stunning because it shows the nudibranch in contact with the colonial tunicate Metandrocarpa sp.
The identifying features of Dendronotus diversicolor are the 4 pairs of gills and a white line that goes from the last gill pair to the end of the tail.
This is a rather unique picture by Ryan Murphy of breeding nudibranchs
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams. Ryan Murphy
General Description:Aconthodorishudsoni is a typical representative of the Dorid Nudibranchs, which are also often referred to as sea slugs. Nudibranchs are sea snails that lack a shell and can vary greatly in coloration and form. That is why they are known as one of the most beautiful marine animals. Acanthodorishudsoni can be easily identified by its transparent whitish body and the yellow stripe running at the edge of its mantle. Its body is covered with conical pipalae, which are also tipped yellow. As most nudibranchs, Aconthodorishudsoni has two long tentacles (called rhinophores) which are used as sensory organs for searching for food or a partner.
Sea slugs occupy the benthic zone. They usually live in the lower intertidal zone and could be found up to 700m in depth.
The dorid nudibranchs (over 3000 species) are widely spread throughout the world. Aconthodorishudsoni, however, could be found only on the Pacific coast of North America.
Size: 1.5 to 2 cm
Feeding:
Dorid nudibranchs feed on a wide variety of organisms: anemones, corals, hydroids, sponges, etc. However, they are highly specialized in their feeding habits. Some nudibranchs can eat only one specific genus or even species! Presently, it is not known what is the exact diet of Acanthodorishudsoni, but biologists believe that it should be similar to the one of the other members of the genus Acanthodoris – bryozoans.
Reproduction:
Sea slugs are hermaphrodites. Usually, they lay their eggs nearby a food source. The incubation period lasts for about 50 days, but can range in accordance to the abiotic factors in the environment. Nudibranchs go through a larval stage and when conditions are favourable, they metamorphose into young adults. This helps them distribute to larger areas.
Biotic Associations:
Although the dorid nudibranchs would be usually found on top of rocks, sometimes they live on other organisms, such as corals, seaweeds, and sponges, and exhibit parasitic relationships.
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
Saxidomus gigantea by Ryan Murphy, April, 2010 This is a common intertidal clam, usually however not found in an ecosystem such as Race Rocks, but rather on sandy or mud beaches. Find the other invertebrates in the image also . Chitons, a top snail, and the tentacles of a sea cucumber.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Bivalvia
Subclass Heterodonta
Order Veneroida
Family Veneridae
Genus Saxidomus
Species gigantea(Deshayes,1839)
Common Name: Buttter Clam
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams. March 15 2010- Garry Fletcher
Domain Eukarya Kingdom Animalia Phylum Mollusca Class Gastropoda Subclass: Opisthobranchia Order Nudibranchia Family Polyceratidae Genus Flabellina Species trilineata Common Name: Nudibranch
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote controlwebcams.
Return to the Race Rocks Taxonomy and Image File
The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.
