Nudibranch breeding and life styles

Firstly the family name (Nudibranchia) is given to these creatures meaning naked gills and is part of largish family called molluscs or gastropod molluscs and is also a sea slug.

Through out the worlds oceans there are in excess of three thousand known species of nudibranchs covering many shapes colours and sizes, the largest recorded is just over 31 centimetres in length.
As these vividly coloured creatures roam the oceans floor they sense their prey via tentacles called (rhinophores) which are located on their heads.

Feeding
These sea slug family members are carnivores so the prey can consist of most any alages, sponges, corals, other molluscs and each other, so basically if it is in the aquarium and sits still long enough they may try and eat it, though most have specific food preferences needed to survive.
Some species of nudibranch have developed a way to harness the power of light by developing a symbiotic relationship with zooxanthellae, Another type of sea slug, called a sacoglossan is able to save and use the chloroplasts found in its diet of algae and all nudibranch derive their colouring from the prey they devour.

Breeding
Nudibranchs are simultaneous hermaphrodites, and can mate with any other mature member of their species. Copulating pairs inject sperm into each other by a penis. Eggs are usually deposited by each individual in a coiled mass on underwater surfaces. A few species emerge from the egg as a crawling juvenile. However, most emerge as free swimming larvae, with a tiny remnant shell. Their lifespan varies widely, with some living less than a month, and others living up to one year.

Defences
The nudibranch has no shell so in defence can absorb toxins from the creature it devours and secrete this as a defensive mechanism later on. They also predate upon anemones, corals and other marine creatures with stinger cells called nematocysts as defences, they store these and can discharge them in defence against predators when needed.
Other nudibranchs use camouflage to avoid detection. Most nudibranchs have intricate and extensive colour patterns to warn predators that they are toxic!


These two were in this tub for only two days before eggs were layed by each nudi.




A few examples of the variety of these creatures.