Large numbers in the rock pools - all seemed to be the common prawn on examination of rostra.
No interactions present.
Agreeing this on the basis of turned up rostrum. I havent read that the turned up rostrum is totally unique to serratus yet(it might be) but it seems to be one feature to look for in P. serratus as opposed to P. elegans anyway. Marlin mentions 2 other similar species but so far I'm not entirely sure about the nature of their rostrums.
Lat/Lng: 51.3877, 1.3671
OS grid ref: TR343707