498 THE BIOLOGY OF MARINE ANIMALS 



fin rays, and is capable of inflicting a very painful wound. This animal 

 bears a conspicuous black warning badge on its dorsal fin, which is the 

 only part visible when the fish rests buried in the sand. The common sole 

 Solea solea, itself a harmless species, mimics the weaver-fish and bears 

 a large black patch on its upper pectoral fin, which it erects vertically. 

 Both species inhabit the same geographical range and have similar habits. 

 Some examples of special resemblances to seaweeds and various animals 

 may now be mentioned. In the littoral zone and on coral reefs there are 



Fig. 11.11. Heniochus acuminatus, a Coral Reef Fish of the 

 Indo-Pacific Region 



many animals which have adopted special protective resemblances to 

 sponges, anemones, corals, alcyonarians, etc. Certain cypraeid gastropods 

 show considerable similarity to the animals upon which they occur. 

 Cypraea pustulata of the Bay of Panama is described by Mortensen as 

 having skin folds provided with small branching protuberances closely 

 resembling the colour of coral polyps ; and Simnia patula, which normally 

 occurs on Alcyonium digitatum, closely resembles the latter in shade and 

 colour. Especially noteworthy are the remarkable resemblances borne 

 by many members of the floating animal communities of the Sargasso 

 Sea to the Gulf weed among which they dwell. For example, the frog fish 



