Let's Learn about Nudibranchs - SIZE
Nudibranchs can vary a LOT in size. So how big or small are Nudibranchs? As adults, they can be as small as a few mm to over 60cm (0.16in to 25in). Let's dive a little deeper and see some examples of the smallest, the World's Largest, and the average size of Nudibranchs.
SMALLEST - The smallest Nudibranch I have seen were TINY Three-Lined Nudibranchs (Flabellina trilineata) while diving the Keystone Jetty Pilings on Whidbey Island, Washington. These grow to a maximum length of 3.5cm (1.3in) and have clusters of bright cerata. Some Nudibranchs never reach more than a few mm even as adults!
Scuba diver pointing out tiny Three-Lined Nudibranchs (Flabellina trilineata). Photo by Hannah Tilley
Closeup of the tiny Three-Lined Nudibranchs (Flabellina trilineata). Photo by Hannah Tilley
Watch the video here:
LARGEST - The largest Nudibranch in the world are the Spanish Dancers (Hexabranchus sanguineus) which can be over 60cm (25in) and weigh over 6kg (14lbs). PT Hirschfield found these ENORMOUS Spanish Dancers including a mating a pair at Pearl Rock in Beqa, Fiji.
AVERAGE - Of the 3,000 species recorded so far, most fall between 2cm (~1in) to 12cm (~5in) however. Below are some good examples to show you scale!
Hooded Nudibranch (Melibe leonina) with finger to show scale. Photo by Hannah Tilley
Scuba Diver with Nudibranch to show scale. Photo by Manolis Patelis.