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Some claim insects evolved from prehistoric crustaceans, and they have secondary antennae like crustaceans, but not primary antennae. Antennae are the primary olfactory sensors of insects [7] and are accordingly well-equipped with a wide variety of sensilla (singular: sensillum). Paired, mobile, and segmented, they are located between the eyes ...
The coxal gland is thought to be homologous with the antennal gland of crustaceans. The gland consists of an end sac (saccule), a long duct (labyrinth) and a terminal bladder (reservoir). [2] There is generally only one pair (two in some spiders), and they open on the coxae of the walking legs [1] or at the base of the second antennae in the ...
The general shape of the antennae is also quite variable, but the first segment (the one attached to the head) is always called the scape, and the second segment is called the pedicel. The remaining antennal segments or flagellomeres are called the flagellum. [17]: 8–11 General insect antenna types are shown below:
The largest of these is the carina, on the morphologically dorsal side of the capitulum, with a pair of smaller scuta and terga on either side below. Further calcification occurs from other centres on the capitulum with the formation of many small scales. The thoracic crustacean appendages are modified into feather-like cirri.
These, like the maxillipeds of crustaceans, are modified legs and not true mouthparts. [2] The forcipules arise from the first body segment, curving forward and to the midline. The tip is a pointed fang, which has an opening from a venom gland. The forcipules are used to capture and envenomate prey.
Spiny lobsters can be easily distinguished from true lobsters by their very long, thick, spiny antennae, by the lack of chelae (claws) on the first four pairs of walking legs, although the females of most species have a small claw on the fifth pair, [6] and by a particularly specialized larval phase called phyllosoma.
The long first antennae, two in number, are used by the males for gripping the females during mating. Afterwards, the female carries the eggs in two small sacs on her body. The larvae, or nauplii , are free-swimming and unsegmented.
Anaspidesidae is a family of freshwater crustacean that is endemic to Tasmania, Australia. [1] The family contains 3 living genera. This group of crustaceans are considered living fossils. [1] They are commonly and collectively known as the Tasmanian anaspid crustaceans. [2] This family is originally called as Anaspididae.