64 



in the open sea, and for these reasons and because it and 

 the active and omnivorous bass and the voracious eel 

 have different feeding habits, these fishes form an 

 admirable trio for the purpose of the fish farmer in 

 France. 



At Comacchio eels and mullet are found to live well 

 together ; these two species form the bulk of the produce 

 of the lagoon. Sand smelts {Atherina boyeri) and 

 Gobies (G. lota), furnish considerable quantities in some 

 years, the former giving from 70,000 to 90,000 kilos per 

 year, the latter from 2,000 to 3,000 kilos. These two 

 fishes apart from the direct contribution they make to 

 the revenue of the fishery are of immense importance as 

 food for the eels — the immense shoals of aquadelles, as 

 Atherina is termed at Comacchio, constituting their chief 

 nourishment during the greater part of the year. The 

 other species of fish which thrive in these fish farms 

 comprise bass, soles, plaice and sea-bream (Spams 

 aura to) but although they constitute a notable propor- 

 tion of the fry which enter from the sea comparatively 

 few survive to maturity. 



Shrimps {Crangon vulgaris) and Carcinus viacnas, 

 the common shore crab of Europe, enter in enormous 

 quantities when the sluices are open for the inontata in 

 the spring and as they also breed freely in the lagoon, 

 they furnish an indispensable and never failing source 

 of fish-food. 



The ability not only to withstand and survive com- 

 paratively considerable variations in the salinity of the 

 waters they inhabit, but to thrive almost equally well 

 whether the salinity be high or low — within reasonable 

 limits — is the most important attribute to be considered 

 when deciding what species are best fitted for culture in 

 marine fish farms. The ponds employed cannot be put 

 in fully free communication with the sea, and hence in 

 dry seasons may tend by reason of rapid evaporation to 

 become comparatively highly saline, while on the other 

 hand the occasional torrential rains and high floods which 

 are factors in the situation in India wheresoever the 

 pond might be situated, are bound to reduce the salinity 

 below the normal at certain seasons. 



Unfortunately there is lack of precise information 

 available on this point. Among European fishes suitable 



