HERRING, GA8PEREAU, SHAD AND OTHER CLUPEOIDS 



107 



SESSIONAL PAPER No. 22a 



/ the fish must have been 30 to 40 days old, they measured 16 :6 mm. (W20 inch) (Plate 

 / VIII., fig. 44), and the rudiments of the dorsal fin are now seen as delicate rays, while the 

 front part of the lower jaw is studded with minute teeth. A maxillary flap hangs 

 from the upper jaw, this maxillary flap being prominent also in the young shad (Plate 



IX. , fig. 19). Further, the notochord, as in the shad, consists of a network of irregular 

 cells, unlike the regular notochordal disks, characteristic of the herring, sprat, &c. At 

 this stage the pre-anal lobe, of great length, still forms a prominent feature, and is 

 probably diagnostic of the gaspereau, though it is prominent in such a form as Am- 

 modytes, the sand-eel. The globe of the eye is now black with pigment and the swim- 

 bladder is visible as a large silvery almond-shaped sac with pigment (black) in its 

 dorsal wall. Pigment is more abundant over the whole of the fish at this stage, the 

 head, cheeks and throat being spotted plentifully with black, amidst which a few yel- 

 low stands of colour pass. In this stage, as in the previous stage, the dorsal fin mem- 

 brane is very narrow, and forms a thin, rather meagre membranous ridge along the back 

 from the shoulder to the tail. The pre-anal fin is still of disproportionate length and 

 breadth, indeed, its breadth almost equals that of the trunk, a very unusual feature in 

 fish larvae, although in the shad it is a fairly prominent structure (Plate IX., figs. 18, 

 19). The tail is more distinctly spatulate, the hind margin being no longer rounded, 

 but markedly flattened. Between this stage 16*5 mm. (W20 inch), and the stages 

 figured on Plate X., fig. 26, when a size of 30 mm. (IJ inches) is attained, no inter- 

 vening stages have been secured. The blunt rounded head, the stout, somewhat short- 

 ened body, and the large size of the eye and the paired fins, are in contrast to the 

 similar stages of the herring (Plate VIII., fig. 4), and the shad (Plate IX., fig. 20). When 

 35 mm. long (If inches) (Plate X., fig. 27), the external features are practically the 

 same, the pi^ent forming two lunate patches at the base of the tail being more 

 marked; but the general translucency of the body is preserved and the pigment con- 

 sists of very minute black specks scattered all over the dorsum, especially on the head 

 and on the tail, a few spots occurring on the premaxilla, maxilla and mandible. Two 

 features are worthy of special attention at this stage, viz., the shortness of the maxilla, 

 which does not extend as far as a line drawn perpendicularly through the centre of the 

 eye, whereas in the shad the maxilla extends considerably behind such a line (vide 

 Plate IX., fig. 24), and in the herring (Plate VIIL, fig. 5) barely reaches such an imagin- 

 ery line, while again the snout is very acuminate and not bluntly rounded as in the 

 shad and Twaite shad (Plate IX., figs. 23, 24). The strong serrations of the middle 

 abdominal scales or scutes, so characteristic of the adult gaspereau, are already well 

 marked (Plate X., fig. 29). A much older stage was obtained in St. John harbour. 

 New Brunswick, about the middle of August, wlien specimens from 3 inches (75 mm.) 

 up to 5 and 6| inches (140 mm.) were secured (Plate X., figs. 28 and 29). The speci- 

 mens could not possibly be the young of the same season, and though one in ten was 

 of the small size first mentioned and a fifth of them of the largest size, all presented 

 much the same features and were practically adult in general external appearance. The 

 scales are comparatively large, and completely clothe the body, and they differ much in 

 form and size from the scale of the sea-herring of the same size (Plate X., compare 

 fig. 30, a gaspereau scale, with fig. 31, a sea-herring scale, both scales being from the 

 dorsum near the base of the dorsal fin). Hardly less distinctive is the series of ab- 



. dominal scutes or middle ventral line of keeled scales. These, in the gaspereau (Plate 



X. , fig.*"^^ are much more strongly pointed and projecting than in the young her- 

 Jfr ring (Plate X., fig. -61^), while the strong anterior process (a) is absent, or represented 



by a mere indication of a process in the posterior bifid margin of the scale. The sides 

 and opercular surfaces are brilliant silvery in appearance, while the dorsum is of 

 a dark purplish blue, thickly spotted with black. The orange or ochre tint, noticed 

 in the early larval fish, still remains as a suffused tinge though far paler than when the 

 gaspereaux are 30 mm. long. The paired and unpaired fine are very deeply spotted 

 with black, whereas in the herring the fins are clear and transparent, and bear no black 



