56
THE ESSEX NATURALIST
Syngnathus rostellatus as a British Fish
BY ALWYNE C. WHEELER
(MS. submitted 9/6/55).
IN September 1954. while on a visit to Felixtowe. Suffolk, I caught two
small pipe-fishes in a dip-net a few yards off-shore. On examination I was
pleased to find that they were young specimens of the 'lesser pipe-fish'—
Syngnathus rostellatus, a species for which there is only one other definite
record for the British coast. This previous record was of five specimens taken
in a plankton net towed in the Thames Estuary (off Southend-on-Sea), in
November, 1933 (Wells 1938). The present specimens were taken in about
four feet of water, over a large sandy patch, although there were weed covered
rocks in the vicinity.
Since this species was first described (Nilsson 1855), it has been recognised
on many parts of the European coast, and Poll (1947) gives its range as from
the Gulf of Grascogne northwards to the Norwegian coast (Bergen) and the
Oresund, but it is most common in the North Sea. It is therefore not surpris-
ing that it should occur on the British coast, and it is undoubtedly more
common there than records would suggest. But, on account of its
superficial resemblance to Syngnathus acus (the commonest of the British pipe-
fish), it has hitherto been confused with that species. The two, however, can
be separated by several characters, the most convenient of which is the number
of body rings (cristae). In S. rostellatus there are between 13 and 16 pre-anal,
and 37 to 4'2 post-anal cristae, whilst in S. acus there are 17 to 21, and 39 to 41.
The two species also differ in size. S. rostellatus being much the smaller,
seldom attaining a length greater than 17 cms., while S. acus grows to a length
of 45 cms.
This confusion led Donovan (1802) to figure a pipe-fish which is probably
S. rostellatus (Smitt 1895), and Day (1880) in his description of S. acus
plainly had specimens of both species. He recognised the differences between
them, for he enumerates a male 41/2 inches long with 13+40 body rings, a female
of 3.1 inches with 15 + 40 (both rostellatus) and another female 7 inches long
with 19 + 44 (the true acus), but concluded—"without further specimens I can-
not resist thinking that the difference in the number of rings may be due
to age."
Examination of the collection of pipe-fishes in the British Museum (Natural
History) has revealed the following additional records for the British coast.
Five specimens from the Firth of Forth, 8 from Yarmouth, 1 from Worthing,
2 from Plymouth. 2 from Poole and one from Blacksod Bay, County Mayo.
Two others are labelled "Wales" and "England" respectively, and two were
purchased at "London market".
References.
Day, F., 1880-1884. Fishes of Gt. Britain and Ireland 2; 259. pl. 144 fig. 2.
Donovan, E., 1802 British Fishes; tab 58.
Nilsson, 8., 1855. Skand. Fn. Fish; 687
Poll, M., 1947. Faune de Belgique, Poissons Marius; 185
Smitt, F., 1895. History of Scandinavian Fishes (ed. 2) 2; 672.
Wells, A. L., 1938. Journ. Animal Ecol. Camb. 7, 1: 122.