A cormorant and pipefish prey

One of us (JM) has a favourite fishing spot on the Helford River. In September of this year (2005) he noted that it was also favoured by a Cormorant that 'patrolled' quite a small stretch of coast - about 100 metres. He observed that the bird had become skilled in locating and catching pipefish, as on three separate visits he saw it swallow a total of no less than 10 of these fish.

This led us to speculate on which species was being caught - and indeed if more than one species was involved. There are six species of pipefish in British waters, 5 of which have been found in the HVMCA.

Manoeuvring these slim fish into the gullet is quite a performance, giving JM time to assess the size. This varied from a minimum of 15cm to a maximum of 30cm, and judging by the frequency of occurrence and size, it seems likely that the species being consumed by the Cormorant, were the Greater Pipefish and the Worm Pipefish.

These elegant, slender fish are described as pipe-like due to their similarity in shape to the clay pipes that were smoked in the 18th century. Instead of scales the pipefish have jointed bone-like rings from head to tail. They usually swim with an eel-like motion, although when feeding they can swim in a vertical position similar to the closely related two British species of sea-horses. The males of pipefish and sea-horses have a special brood-pouch in which the eggs, produced by the larger female, develop and eventually hatch.. Since there are no teeth in their small tubular mouths they capture their minute prey by suction.

Species of pipefish in British waters

	Maximum size
Species	Female	Male	Status HVMCA
Worm Pipefish Nerophis lumbriciformis	15 cm (6")		Common
Straight-nosed Pipefish Nerophis ophidion	30cm (12")	20 cm (8")	Five records
Greater Pipefish Syngnathus acus	46cm (18")	30cm (12")	Fairly common
Nilsson's or Lesser Pipefish Syngnathus rostellatus	17cm (ca. 7")	10cm (4")	One record
Deep-snouted or Broad-nosed Pipefish Syngnathus typhle	30cm (12")	12cm (ca. 5")	Two records
Snake or Ocean Pipefish Entelurus aequoreus	Very large and almo	st entirely oceanic	None

Thanks to Joan Carr and Treve Opie for help in preparation of this note.

John Munday and Stella Turk

Extract from HVMCA newsletter No.31 Autumn 2005