Tag Archive: sea slugs

Phylum: Mollusca
Class: Gastropoda,
Order: Nudibranchia (sea slugs)
Family Tethydidae

Genus/ species: Melibe leonina

YouTube VIDEO  http://youtu.be/Xe2bM2kKm-U

GENERAL CHARACTERISTICS: Color a translucent gray, greenish-gray, or yellowish-gray, with opaque brown hepatic diverticula. Melibe leonina has 4-6 pairs of large, leaflike or paddlelike cerata in two rows down its dorsum and a large oral hood with two rows of filiform tentacles around its margin.

Length up to 102 mm long (4 in), 25 mm (1 in) wide, and 51 mm (2 in) across the expanded oral hood.

DISTRIBUTION/HABITAT: West coast of North America from Alaska to Baja California in eelgrass beds, kelp (especially Macrocystis) beds, harbors. When swimming it is usually upside-down, and undulates back and forth.

DIET:  M. leonina feeds on Copepods, amphipods, and ostracods, as well as small post-larval mollusks. They firmly attache itself to a kelp blade and then sweeps its raised hood downward or to the side. When food lands on the lower surface of the hood, the melibe sweeps together the two sides of the hood, and its fringing tentacles lock in the prey. The hood contracts to force the captured food into the M. leonine’s mouth.

REPRODUCTION and DEVELOPMENT:  M. leonine are hermaphrodites (they have both male and female sexual organs), and fertilization is internal. The animal can lay as many as 30,000 eggs, which are enclosed in a long, gelatinous ribbon.

REMARKS:  Noxious secretions of the melibe smell like watermelon, according to aquarists. They are gregarious animals and probably use it to keep together as well as for defense.  Most predators avoid the noxious secretions of nudibranchs; but the kelp crab is an exception. 

This species has been used for neurological research.



California Academy of Sciences, Steinhart Aquarium, Water is Life 2019

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Ron’s flickr www.flickr.com/photos/cas_docents/sets/72157608597736188/

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/me…

EOL eol.org/pages/454874/details


Phylum: Molluska,
Class: Gastropoda
Family: ‪Aeolidioidea‬ (superfamily of sea slugs, the aeolid nudibranchs)

Genus /species: Aeolidia papillose

GENERAL CHARACTERISTICS: Its color appears to be quite variable, depending upon locale and food resources. This large aeolid grows to about 10 cm(4 in) in length and its body is covered with close obliquely arranged rows of flattened cerata.

Aeolidia papillose 6873953510_5aecc605bd_k

DISTRIBUTION/HABITAT: Common on the Atlantic coast of Europe and North America and the Pacific coast of North America. Also from  both west and east coasts of South America  Found on rocks, or may be on floats or docks often near its preferred prey. Intertidal to 380 m (116 ft) deep.

DIET IN THE WILD: Feeds almost exclusively on sea anemones.

MORTALITY/LONGEVITY: This species is famous for obtaining undischarged cnidae (cells which bear nematocysts) from its Cnidarian prey and moving to the tips of the cerata , where they are likely used for defense. If disturbed they sometimes wave their cerata. If one of the cerata is broken off, muscles within it contract, expelling the nematocysts, which then discharge . The chemical composition of A. papillosa mucus changes and does not trigger a discharge of nematocysts in the sea anemone.

REPRODUCTION/: Nudibranchs are hermaphroditic, and thus have a set of reproductive organs for both sexes, but they cannot fertilize themselves.

REMARKS: Their eyes are simple and able to discern little more than light and dark. The eyes are set into the body, are about a quarter of a millimeter in diameter, and consist of a lens and five photoreceptors.



Ron’s flickr https://www.flickr.com/photos/cas_docents/6873953510/in/album-72157660640336765/

Encyclopedia of Life eol.org/pages/402852/details

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Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Family: Dorididae

Genus/species: Peltodoris nobilis

GENERAL CHARACTERISTICS: Color variable: may be pale yellow to a deep rich yellow or orange. Back is covered with tubercules and dark spots. Fleshy antennae (sensory organs) and a rosette of gills protrude from the back of a sea lemon’s slim, flat body. One of the largest of all nudibranchs; 4 to 4.5 inches (10 to 11.5 cm).

Sea Lemon Nudibranch3124713462_3c7ecb3ff5_b

DISTRIBUTION/HABITAT: found from Alaska to Baja California in
rocky areas, mostly at low intertidal and subtidal depths to 300 feet (91 m). Often seen on harbor pilings. California is well-known for the diversity of nudibranchs found in its coastal waters.

DIET: uses a file-like radula to eat sponges.

Sea Lemon Nudibranch3123887143_7648580fb9_b

REPRODUCTION: like all nudibranchs, is hermaphroditic and can produce both sperm and eggs.

LIFE SPAN: approx. one year


REMARKS: P. nobilis is one several dorid nudibranchs with a fruity, distinct lemon scent usually given off when the animal is handled, thus its common name. When concentrated, the odor repels many predators.

COLOR OF LIFE Note: Concealment by camouflage. Has a bumpy surface typical of those corals and sponges.

Sea Lemon Nudibranch2997671850_b9f4546718_b


California Academy of Sciences Color of Life docent training 2015

Ron’s flickr  https://www.flickr.com/photos/cas_docents/2997671850/in/album-72157608597736188/

Metropolitan Oceanic Institute and Aquarium  www.svsu.edu/~tkschult/moia/sea-lemon.html

Monterey Bay Aquarium  www.montereybayaquarium.org/animal-guide/invertebrates/se…

EOL eol.org/pages/451875/details

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-1AF

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