NUDIBRANCH GILL GUARDING Shell-less but not defenceless The sea is full of hungry mouths, many many hungry mouths either lying patiently in ambush or constantly on the move, in all directions, hunting for any opportunity to take a bite and feed. The last thing any animal needs is to have some attractive piece of their

Plocamopherus ceylonicus displaying the four papilla-mounted bioluminescent globes arranged around the vulnerable gill. ILLUMINATION ENLIGHTENMENT Bioluminescence in Nudibranchs Species of the humble sea slug can possess unusual and extraordinary capabilities such as autotomy, zooxanthellae hosting, kleptoplasty, exploitation of their prey’s defences through nematocyst sequestration and toxin accumulation, not to mention some incredible host mimicking. Another,

CERATA Part 2 – The Multiple Functions In Part 1, an overview of cerata was given together with some examples of what are, and what are not, considered to be cerata and which sea slug taxa possess them. A list of their diverse roles was included. Here in Part 2 those roles (excluding defence –

CERATA: The Multifunctional “Fingers” of Sea Slugs Part 1 – Introduction The term cerata (singular: ceras) is most often associated with the processes that arise from the dorsum of the Aeolidina – the aeolid nudibranchs. However, it is also commonly applied to the processes found on the dorsum of some of the Sacoglossa sea slugs

The Gastropteridae are cephalaspideans or head-shield slugs. It would appear that their “main claim to fame”, bright and dramatic colouration of many aside, revolves around the ability and propensity of many to swim by flapping their parapodia. This behaviour has led to them receiving the common name of “bat-winged slugs”. Behaviour, especially one so demonstrative

When you don’t possess true eyes to recognise the shape of things, to see where you’re going, or what’s coming, then you must certainly have some other highly developed sense to survive. Living in a medium that has thousands of different compounds dissolved or suspended in it, a virtual soup of chemicals, released either intentionally

We all know about the rhinophores of the true nudibranchs – those highly developed chemical-detecting “antennae” located anteriorly on their “head”. Even sea slugs other than the true nudibranchs such as the sea hares, and the side-gilled pleurobranchs have rhinophores. These though are tubes formed by longitudinal rolling rather than the solid form of the

Hexabranchus sanguineus The name says it all. It has six gills – Hexabranchus, and is blood-coloured – sanguineus. This species was originally described from the Red Sea. Specimens from that region are not red and white mottled as in the images posted here but are a deep and uniform “blood” colour. This nudibranch, also known

The Little Scraper Nearly all the sea slugs, just like nearly all the molluscs (except the bivalves), possess a radula in the buccal cavity for feeding. The radula is used not unlike a combination of teeth and tongue to rasp at, puncture, slash or grip the prey for ingestion. Salivary glands assist the action of

The true nudibranchs are divided into two suborders – Suborder Cladobranchia and Suborder Doridoidea. Without doubt the most noticeable external difference between the two is in the appearance of the gills. Here we must generalise of course with the dorids having a circle of gill branches around the anus, sometimes presenting as an arc or