94 ACANTHOPTERYGII. 



Tunny, Couch, Fish. Brit. Isles, ii, p. 86, pi. lxxxii. 



Orcynus thynnus, Liitken, Spolia Atlantica, 1880, p. 460. 



Of moderate age. 



Thynnus coretta, Cuv. and Yal. viii, p. 102 ; Gtinther, Catal. ii, p. 363, 



Young. 



Ancicoti (J Alicorti), Duhamel, Peches, Sect, vii, p. 205, pi. vii, f. 5. 



Thynnus brachypterus, Cuv. and Val. viii, p. 98, pi. ccxi ; Cuvier, Regne 

 Anim. 111. Poiss. pi. xlvi, f. 2 ; Giinther, Catal. ii, p. 363. 



Short-finned Tunny, Couch, Fish. Brit. Isles, iv, p. 425, pi. lxxxii* ; Dunn, 

 Journ. Roy. Inst. Corn. xxii. 



B. vii, D. 13-14/ VI + VIII-IX, P. 31, V. 1/5, A. T V+YII-VIII, C. 32-35, Vert- 



16/23. 



Length of head from 3|.to 4, of caudal fin 5| to 6, height of body 4 to 4| in 

 the total length. Eye — with an adipose lid having a circular opening, in adults the 

 diameter is about 1/7 of the length of the head, while the distance from the 

 eye to the end of the snout equals 1/3 of the length of the head. Lower jaw 

 slightly the longer : the maxilla reaches to beneath the front edge of the eye. 

 Teeth — a single row of small ones in either jaw, a few on the vomer and in a 

 band on the palatines : none on the tongue. Fins — the pectoral scimitar-shaped, 

 and varying in size with age. In the adult it is about 5| times in the total length 

 of the fish : when a little younger, 0. coretta, it is about 5| in the total length of 

 the fish : whereas in the young, 0. brachypterus, it is not more than 1/7 to 1/8. 

 The first dorsal fin reaches about to the origin of the second, while the anal 

 commences under the first free dorsal ray. Scales — cover the entire body, in the 

 adult forming a very distinct corselet which sends backwards three pro- 

 longations. The superior passes along the base of the first dorsal fin : the central 

 one is continued along the middle of the side, and in a groove in it rests the upper 

 edge of the pectoral fin : while the inferior passes along the lower margin of the 

 abdomen to a little beyond the termination of the ventral fin. In young examples 

 the corselet is not so well developed, neither are the posterior prolongations so 

 marked. Air-bladder — present. f Colours — back dark blue, almost black in 

 adults, but having some stripes in the young : gray along the sides and white 

 beneath. The sides are reticulated with fine gray lines, enclosing oval or round 

 spaces. The corselet is rather lighter than the contiguous parts. Jaws dashed 

 with pink. First dorsal fin dusky : the second and the anal pinkish, shaded with 

 gray. Pectoral and ventral dusky, the first with a white posterior edge. Caudal 

 dusky. The younger fish are the lightest coloured. 



Varieties. — The tunny has had many names conferred upon it, due to the 

 considerable modifications which it undergoes during its transformation from 

 extreme youth to old age. 



Names. — Pennant observed that on the coast of Scotland they were termed 

 Mackrelsture, derived from the generic name of " mackerel," and the Norwegian 

 word stcerie or great. Tunny has been considered a derivation respecting its 

 rapidity of movements, or else that the term is of Hebrew or Phoenician origin, 

 in allusion to its great size. Thon in olden times signifying any large inhabitant 

 of the sea, or even the crocodile of the rivers. Aristotle recorded tunnies up to 

 1200 pounds weight, and Belonius states that in 1665 an example was taken off the 

 Spanish coast measuring 32 feet in length and 16 in girth. 



These fishes have been known in various places by different names, in accord- 

 ance with their size, thus along the shores of the Black Sea the very young have 

 obtained the designation of auxid, which signifies such from the time of extrusion 

 from the egg until their first leaving the Euxine. The semi-adults are termed 

 pelamis, which covers the time until their return the succeeding spring. The very 

 large ones go by the name of orcynus. But as the same term is differently employed 

 in different localities, an enumeration of names becomes of but little practical 

 use. Le Thon commun, French. 



t See a detailed description by H. Malm in his "Fauna of Bohuslau," and for the anatomy 

 of the fish see Cuv. and Val. viii, pp. 63-69. 



