Q 36. - Biology

Question

Describe the various superclasses that phylum Arthropoda can be divided into.                                            

                                               

           

Step-by-Step Solution

Answer

Arthropoda include Hexapoda, which are mandibulates with six legs; Myriapoda, which are mandibulates with many legs and include centipedes and millipedes; crustaceans, which are mostly marine mandibles; and Chelicerata, which include spiders and scorpions and their relatives.

Subphylum Chelicerata

Chelicerata includes animals such as horseshoe crabs, sea spiders, spiders, mites, ticks, scorpions, scorpions and scavengers. They are predominantly terrestrial, although some freshwater and marine species also exist. Around 77,000 species of chelicerates can be found in almost all terrestrial habitats.

                                       

Subphylum Myriapoda

Myriapoda includes arthropods with multiple legs. The name is misleading and suggests that thousands of legs are present in these invertebrates, the number of legs usually ranges between 10 to 750. It includes 16,000 species; the most commonly found examples are millipedes and centipedes. 

Subphylum Crustacea

Crustaceans are the most dominant aquatic  arthropods, with approximately  70,000 species of marine crustaceans. Krill, shrimp, lobster, crab, and crayfish are examples of crustaceans. However, there are also a number of terrestrial species of crustaceans: Terrestrial species such as woodlice  roly-polys and potato bugs are also crustaceans. The number of terrestrial species in this subtribe is relatively low.

Subphylum Hexapoda

Insects make up the largest class of arthropods in terms of species diversity and biomass – at least in terrestrial habitats.

Hexapoda describes the presence of six legs (three pairs) in these animals, which separates them from other groups of arthropods that have varying numbers of legs. In some cases the number of legs has been evolutionarily reduced or the legs have been  modified to suit specific conditions like  endoparasitism. The bodies of hexapods are organized into three tagmata: head, thorax, and abdomen. Head segments have mouthparts derived from the jointed legs, the thorax has three pairs of jointed appendages as well as wings in most groups.