Protella phasma

Carol Horne These two little beings were in the branches of the hydroid pictured here and the larger one on the right would have been circa 2mm, the smaller one <1mm. The large one was using the very long 'antennae' to 'whip' the smaller one - couldn't tell if it was attacking it or feeding it. Also on the branches were numerous small brown 'baskets' containing other plankton, which I couldn't get to see, and which the larger being here was again either attacking or feeding. Although possibly too indistinct to see, the large one was very flexible, long and thin body and the length of the 'feelers' it used was as long as itself. The paddle like front legs are clearly visible. I don't even know what to call it, so if someone could point me to a website or reference I'd be very pleased to research it myself. Thanks

Marco Faasse They are skeleton shrimps. It's even possible to see which species: Pseudoprotella phasma. Often seen on this type of hydroid.

Carol Horne Hey, brilliant....how do you know all this? Recommend a reference site?

Marco Faasse I would recommend the Hayward&Ryland book (Marine Fauna of the British Isles). Seems difficult at first but contains a wealth of information. Collins pocket guide to the seashore seems easier but is far less complete. Good sites are the Habitas site: http://www.habitas.org.uk/marinelife/ and the one I'll mention in the next reply.

Marco Faasse This one: http://www.marlin.ac.uk/species.php

Tony Gilbert Yes, it should be the Pseudoprotella phasma as Marco has mentioned. We get a lot of these all over the sponges and hydroids especially in spring time. They are in their millions I reckon. The issue is getting a good shot: http://www.flickr.com/photos/tonyjgilbert-images/7408199806/in/photostream/ I've photographed them with eggs as well. There is another Species, invasive, called Caprella mutica.