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