Skip to content

Characteristics, Habit & Habitat of Elphidium crispum

Systematic Position / Classification

Phylum: Retaria

Class: Globothalamea

Order: Rotaliida

Family: Elphidiinae

Genus: Elphidium

Species: Elphidium crispum

Habit and Habitat

  • It is a free-living, marine, shelled-protozoan or foraminiferan.
  • It occurs in the littoral zone of the sea down to about 600 meters.
  • It is commonly found creeping about on sea weeds.
  • It also occurs in brackish waters.
  • It has many chambered shells and thread-like axopods.
  • It mainly feeds on small algae and bacteria.

General Characteristics

Elphidium crispum labelled diagram
Fig: Elphidium crispum labelled diagram.
  • The size of Elphidium crispum ranges from 200 to 500 micrometers in diameter.
  • It is a shelled protozoan.
  • It exhibits the phenomenon of dimorphism, i.e., Elphidium exists in two distinct forms—large megalospheric and small microspheric forms.
  • The microspheric form is small and multinucleate.
  • The microspheric form exhibits the asexual mode of reproduction.
  • The megalospheric form is large and uninucleate.
  • The megalospheric form exhibits the sexual mode of reproduction.
  • The shell of Elphidium crispum is disc-shaped, flattened, and slightly elongated in one direction.
  • The aperture, or the opening in the shell, is on one side.
  • Elphidium crispum is a benthic species, which means it lives on the sea floor.
  • Elphidium crispum reproduces asexually by dividing into two daughter cells.
  • It can also reproduce sexually by producing gametes.

Locomotion / Movement

  • Elphidium crispum creeps slowly over the substratum on the sea bottom with the help of its reticulopodia.
  • The reticulopodia are arranged in bundles around the shell.
  • With the contraction of distally placed bundles, the body is pulled or dragged forward.

Nutrition / Food and Feeding

  • Elphidium crispum is typically holozoic.
  • It feeds upon minute organisms like diatoms, other protozoans, crustacean larvae, etc.
  • The net-like reticulopodia are thought to secrete an external mucous layer to trap the food organisms.
  • The mucous layer contains proteolytic secretions which paralyze the prey and initiate its digestion even during capture.
  • The captured food, enclosed in a food vacuole, is drawn into the endoplasm by the withdrawal of reticulopodia filaments towards the interior of the body.
  • Digestion is normally completed outside the shell and the products of digestion pass into the endoplasm.

———- THE END ———-

Read More: