Marine Biology

Meroplakton

Meroplankton (temporary plankton)

            The abundance of temporary plankton is  dependent upon the spawning habits of the benthic organisms. This variation in time of spawning of the various benthos i.e some spawn during  different times of the year or some spawn throughout the year, the occurrence of meroplankton is always there[Nazeer1]  in the seawater. Further, meroplanktonic forms are abundant mostly in the inshore waters or neritic waters as this region is in close proximity to the littoral region, where more benthos is known to live. Also as this region is known to be rich in phytoplankton, these meroplankton larval forms will be able to get sufficient food and metamorphose quickly into adult benthos. Further, the length of larval period is also an important aspect which determines the abundance of the meroplankton  in the neritic zones, and this may vary from a few hours, as in the tube worm Spirorbis, to a period of perhaps four or five months, as in Emerita, the sand crab.

            These forms are more diverse than the holoplanktonic forms as the benthic population constitutes more than 98% of total marine organisms. Almost all the benthic species will have planktonic larval stages as meroplankton  and many species are known to have series of larval stages before they become adult . For example, some decapod  crustaceans ( lobsters)  are known  to have more than 18 different larval stages and most have more than one larval stage. Apart from marine benthos, more nektonic species spawn their eggs during different times or throughout the year and their eggs and larval forms  occur throughout the year in the seawater as meroplankton.