Biodiversity & Conservation

A sea spider - Nymphon gracile - General information

Nymphon gracile

Image Steve Trewhella - The sea spider Nymphon gracile with eggs. Image width ca 12 mm.
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Distribution map

Nymphon gracile recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

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Nymphon gracile is not listed under any importance categories.

General information

Key Icon Researched by: Jessica Heard Text page icon Refereed by:

Taxonomy icon Taxonomy

Phylum Arthropoda Arthropods, joint-legged animals, e.g. insects, crustaceans & spiders
Class Pycnogonida Sea spiders
Map icon Recorded distribution in Britain and Ireland Nymphon gracile may be found all around the coast of the British Isles, although it is less common in the east.
Habitat information icon Habitat information Nymphon gracile can be found in the intertidal and sublittoral of rocky shores.
Text page icon Description Nymphon gracile has a smooth body up to 1 cm long. Its body segments are longer than they are wide and the proboscis is at least twice as long as it is wide. The eight legs are long and slender and roughly 3 to 4 times the length of the body. Chelifores of Nymphon gracile have well developed chela and the palps consist of 5 segments, the ultimate and penultimate segments being equal in length. Although the body is translucent, there is a visible, pink alimentary canal. Ovigerous legs occur in both sexes and have prominent toothed spines which are used to clean the surface of the body. Nymphon gracile commonly migrate into the sublittoral to breed during winter months. Males then carry the eggs back to the intertidal zone sometime in March or April. Nymphon gracile generally reach maturity within 5 months and average life expectancy is about a year.

This review can be cited as follows:

Jessica Heard 2006. Nymphon gracile. A sea spider. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 03/09/2010]. Available from: <http://www.marlin.ac.uk/speciesfullreview.php?speciesID=3922>