FISHES 



46. Five-bearded Rockling. Onus muste/a, Linn. 



(Day's Motella mustela.) 



Not at all uncommon in Lancashire waters. I 

 have obtained a medium-sized specimen from 

 the shore in Barrow Channel. 



47. Three-bearded Rockling. Onus tricirrhatus 



(Bl.) 

 Fairly common. 



48. Halibut. Hippoglossus vulgaris, Flem. 



The halibut is very scarce in Lancashire 

 waters. I have not seen a specimen myself from 

 inshore waters. When it does occur it is usually 

 small. It is more often obtained south of the Isle 

 of Man. A fisherman on Bardsey Island told me 

 of a specimen taken on a line which weighed 

 80 Ib. It was sold at Pwllheli for 8;. 



49. Long rough Dab. Drepanopsetta platessoides 



(Fabr.) 



Day, Hlppoghssoldes limandoides, 

 Very scarce in the Irish Sea. I have seen 

 three or four specimens taken about midway 

 between Lancashire and the Isle of Man. It is 

 so uncommon that there is no local name for it, 

 and it is usually called a ' kind of megrim.' 



50. Turbot. Rhombus maximus, Linn. 



Rather uncommon. Small specimens are, 

 however, taken in shallow inshore waters in 

 the shrimp net. We have had it from the 

 inshore waters of Blackpool, from Morecambe 

 Bay, and from Barrow Channel. Turbot and 

 brill in Lancashire waters are usually infested 

 with the tapeworm Bothriocephalus punctatus. 



51. Brill or 'Brett.' Rhombus lce<vh, Rondel. 

 More common than the turbot and with much 



the same distribution. 



52. Norwegian Top-knot. Scolophthalmus nor- 



vegicus, Gunth. 

 (Day's Zeugopterus norvegicus.) 

 There is a specimen in the Fisheries Museum 

 at the University of Liverpool which is probably 

 local. 



53. Bloch's Top-knot. Scolophthalmus unimacu- 



latus (Risso.) 



(Day, Zeugopterus unimaculatus.) 

 Scarce. Two specimens were caught by 

 Capt. Wignall near the Morecambe Bay light 

 vessel in 1894. This is the only recent record I 

 am aware of. 



54. Muller's Topknot. Zeugopterus punctatus 



(BL) 



This is the commonest Topknot in Lan- 

 cashire waters. Fishermen have no local name 

 for any of these little flukes. They are often 

 caught in the shrimp nets, especially in Morecambe 

 Bay and about the Ribble Channels. 



55. Megrim or ' Magrim.' Lepidorhombus mega- 



ttoma (Donovan.) 



Not uncommon, but not abundant enough in 

 Lancashire waters to be of economic importance. 



56. Scald-fish. Arnoglossus laterna (Walb.) 

 More abundant than the megrim which it 



resembles. 



57. Plaice. Pleuronectes platessa, Linn. 



Very abundant in Lancashire waters. The 

 most valuable fishery in strictly local waters 

 is that for the plaice. It is usually small and 

 immature here on account of the active exploita- 

 tion of Lancashire waters by fishermen. It is in 

 all probability this excessive fishing which has 

 produced the apparent correlation of the size of 

 the fish with the depth of the water in which it 

 is found. Generally speaking, the size of a plaice 

 got in the Irish Sea varies directly (roughly of 

 course) with the depth of water. Within the 

 three mile territorial limit the plaice obtained in 

 the trawl nets are small from 8 to 1 1 inches. 

 Occasionally a large fish may be found, but not 

 often. The plaice becomes sexually mature 

 at about 15 inches in total length in the female, 

 and about 12 inches in the male. It is very 

 rarely that such sexually mature fish are caught 

 within the territorial waters. It is, however, to 

 be noted that the cause of this distribution may 

 not be that large fish find a natural habitat in 

 deep water only, but rather that because of the 

 great amount of fishing in inshore waters these 

 large plaice have been ' fished out.' As a matter 

 of fact, we find that in such an area as Luce Bay 

 on the south coast of Scotland, where trawling is 

 prohibited, large plaice from 15 to 22 inches long 

 are relatively abundant. There is not the same 

 intensity of fishing in offshore waters as within the 

 narrow zone of territorial waters, and as a con- 

 sequence we find that large plaice are found on 

 these offshore grounds. 



There are no doubt very definite migration 

 habits in the case of the plaice (and of course 

 other flat fish), but so far these have been made 

 out only very imperfectly. The Lancashire Sea 

 Fisheries Committee have, however, been making 

 extensive experiments quite recently with a view 

 to determining the migration paths of the plaice, 

 and some interesting results have been obtained. 

 The fish are marked by fastening a little num- 

 bered brass label to the body by means of silver 

 wire. Records are then made of the size of the 

 fish, the number of the label, date, place, and so on, 

 and the fish is liberated. Experiments of this 

 kind have only been made during the winter 

 months, but they seem to show that the plaice in 

 the inshore Lancashire waters move along the 

 shallow coast waters during the early part of the 

 winter, and finally come to rest in the bays and 

 estuaries. Most of the liberated and marked plaice 

 have been recovered from Morecambe Bay, the 



183 



