Note on a Sailfish (Istiophorus Americanus Cuvier and Valenciennes) New to the British Fauna

Extract

About 9a.m. (flood tide) on 17th August,1928, a large sailfish was captured in a dying condition in the main channel of the Yealm estuary, South Devon, opposite the Yealm Hotel, about a mile above the Yealm Bar. The fish was carefully packed up by Mr. V. C. Wynne-Edwards, and promptly despatched to the British Museum (Natural History), where the plaster-cast shown in the accompanying illustration (Fig. 1) was prepared by Mr. S. Stammwitz. The specimen was then cut into two pieces and preserved in alcohol.

Owing to the difficulty of preserving these large fishes in museums, except as stuffed skins, and to the marked changes which they appear to exhibit at different stages of growth, our knowledge of the group which includes the swordfishes, sailfishes, and spearfishes is decidedly limited, and the identification of species is a matter of some difficulty.

In a recent monograph, Jordan and Evermann distinguish nine species of Istiophorus, of which five are said to be new to science. The descriptions of four of these new species are based solely on photographs, the fifth being described from a plaster cast in the museum at Honolulu. As suggested by the authors themselves, some of the characters used by them in their key to the species may be “matters of age not indicating specific distinction.” According to this key, the present specimen from Devonshire would appear to be referable to one of their new species—I. maguirei from the West Indies, but, so far as I am able to judge from the description and photograph, there seems to be no valid reason for separating this from I. americanus, which is found on the Atlantic coast of America from Brazil northwards to Cape Cod and beyond.