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Part III. — Fifteenth Annual Report 



before assuming the condition just noted in that of 30 mm. from Loch- 

 maddy. The smallest of these range from 9*5 to 19 mm., but though 

 they agree with the present species in pelagic dress, there may be a doubt. 

 Not so with one of 25 mm. on the same date, and in the same locality, 

 viz., October 9th, in the Moray Frith. The dark bluish-green dorsum 

 and the silvery sides are as in the other species ; but the depth of the 

 trunk in front of the tail, and the small labial barbels, together with the 

 condition of the first ray of the anterior dorsal, place the identity beyond 

 question. Similar characters are present in an example 28 mm., procured 

 in the same region on the 6th of October, though the first ray of the 

 anterior dorsal is more slender. At 32 and 34 mm., in the same Frith, 

 on the 26th and 23rd of October, all the features are better indicated, 

 such as the proportional size of the head and eye, the somewhat thick 

 and slightly pro De-pointed first ray of the anterior dorsal, which projects 

 beyond the rest, the barbels, and the depth in front of the caudal fin. 

 The steel-grey of the dorsum, and the silvery sides, are well marked ; but 

 the latter, with the exception of the abdomen, is minutely dotted with 

 black points, so as to have a granular appearance. The ventrals are 

 often injured at the tip, and young parasitic crustaceans (Caligi) cling 

 to these and other parts, e.g., the cheeks. Lastly, one of no less than 

 40 mm. comes, like several of the latter, from the surface, though from a 

 different locality, viz., near Inchkeith. The colours agree with the 

 foregoing, and the granular black pigment of the sides has now invaded 

 the first half of the posterior dorsal fin. It is thus apparent that other 

 questions than that of size determine the change of habit and colour in 

 this species. A similar example, 39 mm. long, comes from the stomach 

 of a cod in August. 



Of those which present the change just mentioned, two were obtained 

 amongst the rocks on the 26th July, and measure respectively 35 and 42 

 mm. All trace of the silvery hue has gone ; and the entire body, as well 

 as the second dorsal fin, is minutely dotted with black chromatophores, 

 those on the abdomen — both laterally and ventrally — being distinctly 

 larger. The first rays of the anterior dorsal still shows a slight probe- 

 point, but the ventral fins are injured. 



Another, of 44 mm., also procured amongst the rocks in October, presents 

 a silvery belly, and more or less silvery sides, with the usual brownish 

 hue elsewhere ; the sides, but not the abdomen, being very minutely dotted 

 with black chromatophores. Considerable variations are therefore ex- 

 hibited by the five-bearded rocklings in this condition. 



In January young five-bearded rocklings of a brownish hue, and of 

 the following lengths, are met with between tide-marks : — 37*5 mm., with 

 silvery sides, minutely speckled with black ; 40 mm., also silvery, and 

 with similar black specks; 43 mm., without silvery lustre, and with bold 

 black chromatophores all over the body and fins, while the filament of the 

 first dorsal is long ; 52 mm., without silvery lustre, and with black specks 

 all over. All these are the young of the preceding season. It is possible, 

 also, that one of 70 mm., with black specks all over the head and body, as 

 well as faintly on the fins, may be an early one of the same season as the 

 foregoing. In April, again, young rocklings of If inches are occasionally 

 met with at the surface. One of 80 mm., in July, between tide-marks 

 (Guernsey), appears to be a continuation of the series. In August, at St 

 Andrews, the smaller examples range from If to 4f inches ; while at 

 Lochmaddy the higher limit is 5 inches during the same month. The 

 larger are probably in their second year. The same may be said of those 

 at 103 mm. in February, and of 110 and 133 mm. in November. Those 

 of 6 J inches are somewhat older. 



