284 THE BIOLOGY OF THE SEA-SHORE 



(b) To spawn in fresh water ; larvae descend. 



1. Lamprey : supposed not to return alive. 



2. Sturgeon : has been known to spawn in the brackish 



water area of the Delaware in cold seasons. 



3. Salmonidas : salmon, sea trout, white trout. 



n. Species particularly affecting shore life but not 

 spawning within tide-marks : 



I. Conger. 2. Various Cyprodontidse. 3. Mullet 

 {Mugilspp.). 4. Codling (Gfl^i/^spp.). 5. Rocklings (0«m5 

 spp.). 6. Sand Eels {Ammodytes spp.). 7. Flat-fish (Pleuro- 

 nectidae), Plaice, Dab, Flounder, Topknot. 8. Skate, etc. 

 9. Bass. 10. Dragonet (C. lyra). 11. Weevers (various); 

 also many others on different shores. 



HL Shore-spawning species : 



I. ¥{itttTi-Qp\nt&st\Qk\th2ic\i{Spi7iachiaspinachia). 2. Pipe 

 Fish. 3. Atherina spp. 4. Wrasse (various). 5. Gobies 

 (various). 6. Cottus scorpius. 7. Agoniis cataphr actus. 

 8. Cychptenis lumpus. 9. Bullheads. 10. Butterfish {Cen- 

 tronotus). 11. Sucker Fish {Lepadogaster). Note the 

 absence of edible forms. 



The edible Crab is also a migrant, moving into deeper 

 waters during rough winter weather, although young forms 

 that can hide and protect themselves effectively may be 

 found within tide-marks at almost all times. 



Shore Molluscs. — The Mussel and Oyster find their 

 optimum natural conditions just below low-water mark 

 (whence they are obtained by rake or dredge) and above it 

 have to be catered for in special spots or by artificial aid, 

 in " layings " for fattening, etc. Only the beds that can be 

 hand picked can be regarded as coming strictly within our 

 province, but these include many extensive mussel-beds 

 and practically all the cockle-beds that are utilised ; also 

 the winkle grounds. The taking of all these is regulated 

 by Bye-laws which aim at conserving the beds from 

 depletion by protecting the young forms, and the adults 

 during spawning periods. 



Some idea of the commercial value of the mussel may be 

 gathered fiom the following figures. Before the war, 50 



