07/11/2020
Nudibranchs: a group of soft-bodied, marine gastropod molluscs which shed their shells after their larval stage.
• Noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown," "marigold," "splendid," "dancer," "dragon," or "sea rabbit."
• About 3,000 valid species of nudibranchs are known.
• "nudibranch" comes from the Latin nudus = naked; and the Ancient Greek bránkhia = gills
• The name nudibranch is appropriate, since the dorids (infraclass Anthobranchia) breathe through a "naked gill" shaped into branchial plumes in a rosette on their backs.
• Nudibranchs are often casually called sea slugs, as they are a family of opistobranchs (sea slugs), within the phylum Mollusca (molluscs), but many sea slugs belong to several taxonomic groups which are not closely related to nudibranchs.
A number of these other sea slugs, such as the photosynthetic Sacoglossa and the colourful Aglajidae, are often confused with nudibranchs.
• Nudibranchs occur in seas worldwide, ranging from the Arctic, through temperate and tropical regions, to the Southern Ocean around Antarctica.
• They are almost entirely restricted to salt water, although a few species are known to inhabit lower salinities in brackish water.
• Nudibranchs vary in adult size from 4mm to 600 mm (0.16" to 23.62").
• Nudibranchs have cephalic (head) tentacles, which are sensitive to touch, taste, and smell.
• Club-shaped rhinophores detect odors.
• Nudibranchs use a variety of chemical defences to aid in protection, but it is not necessary for the strategy to be lethal to be effective; in fact, good arguments exist that chemical defences should evolve to be distasteful rather than toxic.
• Nudibranchs are hermaphroditic, thus have a set of reproductive organs for both sexes, but they cannot fertilize themselves.
• Mating usually takes a few minutes, and involves a dance-like courtship.
• Nudibranchs typically deposit their eggs within a gelatinous spiral, which is often described as looking like a ribbon.
The number of eggs varies; it can be as few as just 1 or 2 eggs, or as many as an estimated 25 million.
All of these pictures taken around the divesites of Pulau Mabul- Borneo, Malaysia.
Enjoy....
