Two more paragraphs from Assignment 13
Original
Ctenophores are known as the important
carnivorous gelatinous zooplankton, and also for their weak capability of
swimming against the currents. Currents often serve as one of the major physical
factors affecting the distribution patterns and population dynamics of
zooplankton like ctenophores. Even though the swimming capability of ctenophores
is so weak in comparison with the external forces, it still acts an important
force to help them stay in, or move into, the food-rich areas in foraging
behavior and also in the vertical migration behavior.
There have been some arguments debating on
active or passive forces on the aggregation and population distribution patterns
in the estuaries, embayments, and pelagic areas. It has been generally
recognized that the advective transport is profoundly affected by the current
conditions, and the vertical distribution patterns are provided by the swimming
ability of the plankton themselves. Actually, it is still unclear about the
mechanisms controlling the distribution patterns and population retention of
various kinds of ctenophores in different environmental scales.
Sample revision by K. Rahn
Ctenophores, which are important
carnivorous gelatinous zooplankton, cannot swim well against currents.
Consequently, currents are one of the major physical factors affecting the
distribution patterns and population dynamics of ctenophores. Still, ctenophores
can swim well enough to help them stay in food-rich areas or migrate into them,
and to migrate vertically as needed.
There has been debate over whether the
forces controlling the aggregation and population distribution in estuaries,
embayments, and pelagic areas are active or passive. It is generally recognized
that advective transport is dominated by currents, but vertical transport by the
swimming of the plankton. However, the mechanisms controlling the distribution
and population retention of various kinds of ctenophores on different
environmental scales still remain unclear.