MARINE BIOLOGICAL STATION AT PORT ERIN. 93 



jecting above the surface. Prawns, on the other hand, 

 are active during the day, prowling about constantly in 

 search of food. They live amongst rocks and sea-weed. 

 While alive their bodies are transparent or pale green, 

 usually beautifully marked with blue, and sometimes 

 green, yellow and purple lines. It is only after death 

 that the prawns become opaque, and more or less red in 

 colour. Shrimps are not so transparent when alive, and 

 do not become so red when boiled. They are grey, and 

 are usually speckled and mottled with black and white so 

 as to be exactly of the same appearance as the sand in 

 which they live. As the figure shows, the prawn has more 

 of a hump on its back than the shrimp, and can be easily 

 distinguished by the long spiny snout or " rostrum " 

 between the eyes. There are many other differences, and 

 it must also be remembered that we have several kinds of 

 shrimps and several different kinds of prawns in our seas. 

 The lobster (Homarus vulgaris) and the Norway lobster 

 (N ephrops norvegicus) are allied forms commonly caught 

 at Port Erin. The lobster produces from ten to twelve 

 thousand eggs at a time, which adhere to the legs on the 

 under surface of the tail of the female for many months 

 until they are hatched. Countless millions of embryo 

 lobsters are lost every year through the " berried " females 

 being sent to market, which might be saved if the eggs 

 were cut off and reared in hatcheries. 



There is one little prawn, Hip -poly te (or Virbius) 

 varians, which is found amongst sea-weeds and in pools at 

 Port Erin, and which is of most varied colour according to 

 its surroundings. Specimens living amongst green weeds 

 are bright green in colour, and even the eggs laid by the 

 prawn are green ; when amongst brown weeds, as it often 

 is, it is of a dark brown colour, and when in red and 

 variegated weeds it is red, or speckled with various 



