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Facts about Bullock's Hypselodoris Nudibranch
[Phylum: Mollusca] [Class: Gastropoda] [Order: Nudibranchia] [Family: Chromodorididae]
Hypselodoris bullockii is a medium-sized nudibranch which is usually identified by its purple or pink body colouring and bright orange rhinophores.
This segment contains information about Hypselodoris bullockii sea slug, including where they live, what they eat, and how they reproduce.
Habitat and Range of Hypselodoris Bullockii
Like most nudibranchia, this dorid nudibranch thrives best in tropical or warm water environments.
Thus, the best place to find these shell-less marine gastropod mollusks is the shallow regions of the central Indo-Pacific, especially:
- Indonesia (especially Bali dive sites)
- Japan (e.g. Okinawa)
- Malaysia (e.g. Sabah)
- The Philippines (e.g. Anilao, Palawan Island)
Pro Tip: Divers often mistake the features and characteristics of Hypselodoris bullockii with several other related species, such as Hypselodoris variobranchia, Hypselodoris violacea, as well as Hypselodoris iba (not related).
Bullock's Hypselodoris Characteristics
In general, the nudibranch phylum is not one of uniform colouring. Nevertheless, the pink, blue, and purple hues of this particular specimen help to distinguish it from others.
Hypselodoris bullockii can grow to seven (7) centimetres in length (about 3 inches). Most have a continuous white line running around the edge of the mantle and chemosensory organs (called gills or rhinophores).
The retractile gills and contractile rhinophores vary in size and colour, ranging from pink to translucent pale cream, orange, and light yellow.
What Do Sea Slugs Eat?
Nudibranchs are carnivorous and they get their impressive bright body colouring from the compounds in the food that they eat. They eat using a radula with tiny teeth. They use it to scrape substrate and graze mostly on algae and sponges.
Nonetheless, their diet may also include a combination of:
- Anemones
- Bryozoa (filter feeding invertebrates)
- Coral polyps
- Barnacles
- Fish eggs
- Hydroids
- Other sea slugs
- Sea sponges
- Tunicates (sea squirts)
Fun Fact: Some species of nudibranch are picky eaters, often only feeding on specific food types or even a single source of prey.
Nudibranch Reproduction
The fact that nudibranchs are simultaneous hermaphrodites means that they possess the reproductive sex organs of both male and female.
Being hermaphroditic means they can mate with any mature individual of the species. This is vital to maximise the mating activity, especially because they do not move far on the seabed.
Put another way, finding a mate is difficult and, in general, they are marine creatures that live a solitary lifestyle.
When mating, they can normally mate with any adult passing nearby. By laying a mass of spiral-shaped or coiled eggs, the young hatch as larvae swimming freely in the ocean. They will eventually come to rest on the ocean floor and live their adult life.
Interesting Fact: Sea slugs have become extremely important to the development of some medications. In fact, scientists are actively studying how the nudibranch nervous system works as part of further research.
Related Information and Help Guides
- Blue Glaucus Facts and Species Information with Pictures
- Chromodoris Lochi Facts and Information with Pictures
- Why is the Cone Shaped Snail a Dangerous Mollusk?
Note: The short video [2:37 seconds] presented by "Underwater World Philippine Sea" contains extra fun facts and information about Hypselodoris bullockii nudibranch.