Green nereid (approx 15cm) found in the lower eulittoral under chalk boulder. Not seen this guy here before. Not recorded on MarLIN at all?
No interactions present.
I suspect you are right. But how can we be certain when they are so difficult to separate.
I have rudely offered an agreeable ID.
"With the biggest nereid worms, if photographed with a good macro lens (and in water), you would see the length of the antennae.
The classical way to identify nereids is by the number shape and pattern of the small teeth on the eversible pharynx. Although this seems very technical sometimes gentle pressure behind the head will cause the pharynx to be everted and it can be photographed. After that its generally high power microscopy to see details of the individual limbs(parapoda) and the chaetea they carry.
Some idea of the detail thats needed can be found on pages from a project we ran some years ago in Thailand. Different species but same problems" Mike Kendall in 2011 - here http://www.ispotnature.org/node/123250
THREE MARINE PROJECTS
Lat/Lng: 51.3836, 1.3217
OS grid ref: TR312701
lower eulittoral under chalk boulder