344 



Report on the Probable Ages of Young Pish collected 

 by Mr. Holt in the North Sea. 



By 



J. T. Cnnningham, 91. A. 



During the past summer Mr. Holt has sent nie from time to time 

 young specimens of fish which he has collected, in order that I might 

 report upon the evidence which they aiforded as to the rate of 

 growth of the various species in the North Sea. He has also sup- 

 plied me with a complete list containing the names and the measure- 

 ments of all the specimens he has collected, including many others 

 besides those sent to me. I have simply studied the specimens and 

 the list, and endeavoured to estimate the probable ages of the speci- 

 mens. The necessary information as to the limits and duration of 

 the spawning pei'iod in the case of each species has also been sup- 

 plied to me by Mr. Holt. I have registered below the observed 

 specimens of each species separately in the chronological order of 

 their capture. All have been collected in the course of the current 

 year. 



The principal sources whence these specimens were obtained were 

 the shrimp nets worked on the sands at Cleethorpes, the shrimp- 

 trawls in the Humber, Grimsby Market, and the deep sea trawling 

 grounds. The shrimp-nets are of two kinds — the shove-net worked 

 by hand, the fisherman wading in the water ; and the cart-trawl,* 

 which is drawn by a horse. The shove-net is ten feet wide at the 

 lower end, the cart-trawl is larger. In Mr. Holt's list there are 

 records of fish taken in these nets at the end of April, in May, in 

 June, in July, and in September. The fish obtained from them 

 were most numerous at the end of April, when they consisted of 

 hundreds of small plaice, with a few flounders, dabs, soles, turbots, 

 brill, and smelt. With these were numerous valueless fish, such as 

 gobies and dragonets, which need not here be considered. The 

 majority of the small plaice were 1^ to 3 inches long, and I think 

 there is little doubt that they were derived from the same year's 

 spawning, which commenced in January. None of the other 

 * Locally termed a " shrimp-seine " {vide p. 387). 



