Top of the list for many scuba divers who are keen on underwater photography, especially macro, are beautiful nudibranchs. These stunning critters are part of the sea slug family and noted for their indulgent beauty and intricate display of patterns, shapes and colours. The delicate, flower-like protrusions on their backs are exposed gills (nudibranch means ‘naked gill’).
Ranging in length from just a few millimeters to a few centimeters, they are often hard to spot but the keen-eyes of experienced divers can often seek them out. The nudibranchs’ vibrant colours appear to have evolved from the need to camouflage and defend themselves against predators such as fish. The nudibranchs feed on coral, sponges and sea anemones and their life span, which ranges from as little as one week to as long as one year, depends on the food sources available to them.
These fascinating wonders of nature are hermaphrodites, in possession of both male and female reproductive organs. Nudibranchs cannot, however, fertilise themselves; mating couples may fight one another as if dancing a waltz over who is the male and who is the female. The impregnated nudibranch can produce up to one million eggs that can sometimes be seen on the reef laid in spiral, ribbon-like formations.
There are over 2,000 known species of nudibranch inhabiting all of the world’s oceans. During Kenya’s warm season from December to March, the reef can become awash with these radiant creatures, a wonderful sight to behold.
Next time a slug is spotted on the grass or in the garden, think of it’s beautiful underwater cousins waiting to be spotted at the incredible dive sites in the Diani Beach area of Kenya.