Marine Biology (2+1)

Introduction

Nekton comprise  all the fast and free swimming animals of the pelagic waters.  The term "nekton" was coined by Ernst Haeckel (1890) and it is derived from the Greek word nekton, which means "swimming". These nekton are provided with efficient locomotory organs, called fins, and hence they are not at the mercy of currents.  Most nekton are carnivores (flesh eaters) and predators (organisms that kill and eat other animals) and some are scavengers (flesh eaters that don’t kill what they eat). Often, predators will eat dead animals if they are available. A few nekton are carnivorous filter feeders (animals that filter large volumes of water to obtain their food, which is usually zooplankton) e.g. baleen whales.

                The nektonic animals include chordates and invertebrates such as molluscs and arthropods. There are no plants under this category. These animals are of different sizes and able to migrate freely throughout the oceans.  They posses a variety of feeding habits and most of them feed on planktonic organisms (both phytoplankton and zooplankton) found in the marine and fresh waters.  The locomotory organs are not only used to maintain their positions against the water movements for quite some time but also used to pursue  prey, escape from enemies and for undertaking long distance migrations. These animals are having streamlined body with slime cover to reduce resistance while moving through the water The musculature, nervous system and vision are the special adaptations found in the nektonic animals, which help them to lead nektonic life.