CRUSTACEANS

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Context

• An ongoing study on deep-sea crustaceans off the Indian coast has led to the discoveries of previously unknown crustacean parasites.

Discoveries made

The discoveries included:

1. A new family named Uranoscopicolaidae
2. A new genus and species named Hirodai ohtsukai
3. A new genus and isopod species named Glyptothoa sagara
4. A new isopod species named Elthusa aquabio, and
5. A flesh-penetrating parasitic copepod named Cardiodectes vampire.

Crustaceans

• Crustaceans belong to the subphylum Crustacea and form a large, diverse group of arthropods.
• This include decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp.
• The crustacean group can be treated as a subphylum under the clade Mandibulata.
• It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea.
• The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans (oligostracans and multicrustaceans).
• Like other arthropods, crustaceans have an exoskeleton, which they molt to grow. They are distinguished from other groups of arthropods, such as insects, myriapods, and chelicerates, by the possession of biramous (two-parted) limbs, and by their larval forms, such as the nauplius stage of branchiopods and copepods.
• One of the defining characteristics of crustaceans is their jointed appendages. These limbs are adapted for various functions, such as walking, swimming, grasping, and feeding. The number and structure of their appendages vary across different species.
• Most crustaceans are free-living bottom feeders aquatic animals, but some are terrestrial (e.g. woodlice, sandhoppers), some are parasitic (e.g. Rhizocephala, fish lice, tongue worms) and some are sessile (e.g. barnacles).
• The group has an extensive fossil record, reaching back to the Cambrian.
• Many crustaceans have specialized sensory organs, including antennae, that allow them to detect changes in their environment. These sensory structures help them locate food, mates, and navigate their surroundings.
• Crustaceans contribute to the balance of ecosystems as prey for larger animals and as scavengers that help clean up decaying matter. They also act as filter feeders, consuming microscopic algae and plankton, thus regulating water quality.
• A fascinating ability of many crustaceans is their capacity to regenerate lost appendages. If a limb is damaged or lost due to predation or injury, they can regrow a new one through a process called autotomy.
• Several crustacean species, such as certain crabs and lobsters, exhibit intricate social behaviors. They establish dominance hierarchies, engage in courtship rituals, and communicate with each other using visual displays and chemical signals.