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The anterior of the two or three main divisions of the body of certain invertebrates, especially the cephalothorax of an arachnid.

[pro- + Greek sōma, body; see teuə- in Indo-European roots.]

pro·so′mal adj.


(Zoology) relating to a prosoma
References in periodicals archive ?
Sperm was collected by making 2-3-cm cuts into the soft part of the prosomal ventral cuticle from the base of the appendages toward the lateral margin.
Mucor fragilis on Latrodectus geometricus' prosomal cuticle around cervical grooves and eyes; subject imaged 3 days after inoculation.
The calanoids, hereafter referred to as copepods, were further divided by size: 1) small copepods (<2 mm prosomal length [PL]); and 2) large copepods (>2 mm PL).
Harvestmen (Opiliones) have a distinctive pair of prosomal exocrine glands opening to the surface via ozopores usually placed in the vicinity of the second leg pair.
2005) reported mean prosomal width (PW) for adult females in Pleasant Bay, Massachusetts was 230 ram.
The large prosomal nerve mass that supplies innervation to the musculature of the legs and fangs is located in the anterio-ventral region of the cephalothorax (Foelix 1996; Punzo & Punzo 2002) and damage to this nerve mass coupled with the loss of hemolymph may have accounted for the collapse of the spider.
The smallest 14 animals (prosomal width: 16-18 cm) were assigned to the laboratory running wheel (LRW) group; the smallest animals were selected for this group because pre-constructed running wheels could only fit animals of prosomal width less than 18.
2]) of the relationship between prosomal width and weight for horseshoe crabs (Limulus polyphemus), loge(Wt)=[log.
Ventral prosomal complex of male with coxae of legs II and IV meeting in the midline, but coxae I and III not so (Fig.
The sex, prosomal width (PW; to the nearest 1 mm), and weight (to the nearest 10 g) were recorded from a sample of individuals that were collected from the vicinity of each breeding beach.
Large prosomal exocrine scent glands, also called defensive or repugnatorial glands, are an important synapomorphic character of Opiliones (Martens 1978).
Limb lengths of both populations were standardized to a mean prosomal wet mass of 0.