usually stratified. For example, in southern Florida Rhizophora is 

 located alony the lower boundary of the intertidal zone, then, closer to 

 tlie shore, Avicennia is seen. In the tropics, there Are as many as five 

 zones. The fauna of mangrove stands is not distinguished by great 

 variety, particularly the infauna, which is primarily a result of the 

 shortage of oxygen in the semiliquid ooze, ^bst characteristic are the 

 crabs Portunidae, Grapsidae, Ocypodidae, many of which construct 

 burrows, expelling a plug from the soil; the fish dre the Periophthalmus 

 and Boleophthalmus and the Gobiidae, and the gastropods Neritidae and 

 Littorinidae (particularly Li ttopinopsis ) are present, as well as 

 oysters, and certain polychaetes. tony animals utilize the leaves and 

 trunks of the mangroves as substrates. The invertebrates are dominated 

 by detritophages, sestonophages (cirripedia and oysters) being 

 encountered only in the lower portion of the intertidal zone (Sasekumar, 

 1974). 



In the temperate zone, in low places protected from the surf, salt 

 meadows or marshes are frequently formed. In contrast to mangrove 

 stands, marshes are not located in the intertidal zone, but above it, 

 and only certain halophilic plants frequently occupy the upper portion 

 of the littoral zone. The lower portion of the intertidal zone is 

 either populated with eel grass ( Zostera ) or contains no macrophytes at 

 all. This type of silty-sandy littoral below the marsh zone is referred 

 to as the tidal marsh. Mangrove stands and stands of halophilic plants 

 are different formations with different abiotic and physionomic 

 features. The only similarity is that the halophilic grasses and their 

 fauna and algoflora also consolidate the semiliquid bed and facilitate 

 its gradual conversion to soil. The pioneer of the higher plants in the 

 upper intertidal zone and in the sublittoral in temperate waters is 

 usually the halophyte Salicornia . The bonding of silt particles is 

 facilitated by the Corophium volutator amphipods and the mucus- 

 liberating algae which settle here. The halopohytes are followed by 

 multiannual plants such as Puccinella maritima , plus other salt-tolerant 

 species which settle on the substrate which they prepare: 

 Aster trifolium , Plantago maritima , Armeria maritima , etc. 



Sandy, silted shoals, not subject to strong wave action, are 

 significantly more productive than open sandy beaches, which are poor in 

 detritus. Whereas the surf zones of sandy beaches are dominated by 

 euryphages, which can feed on fresh and decomposed plant and animal 

 residue, as well as living animals, silty-sandy shoals can support a 

 large number of detritophages which swallow the soil of the bed and sorb 

 detritus from the surface increases sharply. Silty shoals, completely 

 protected from the surf in some estuaries, lagoons and closed bays are 

 still more richly populated; in addition to the infauna, rich epifauna 

 develops, represented by the Littorinidae, Potamididae, mussels and 

 oysters, on which barnacles and other epifauna can develop and, in the 

 tropics, crabs, sea cucumbers and sea urchins. 



The greatest biomass is that of the sestonophages--the mussels and 

 oysters, which frequently form continuous settlements, f'bst of the 

 remaining representatives of the epifauna collect detritus from the 

 surface of the bed. Various species living in the mass of the bed 



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