prosoma

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prosoma

[prō′sō·mə]
(invertebrate zoology)
The anterior part of the body of mollusks and other invertebrates; primitive segmentation is not apparent.
References in periodicals archive ?
The purpose of the OU group = 14; prosomal width: 19.1 [+ or -] 0.4 cm, mean [+ or -] SEM) was to monitor activity in animals exposed to a natural photoperiod and constantly replenished estuarine water.
Eggs, if present, escape the carapace and are visible because of internal pressure or as a result of gently pressing the prosomal angle.
We recorded prosomal width (to the nearest 1 ram), weight (to the nearest 10 g), sex, and maturity stage for all or a subsample of horseshoe crabs at each site.
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 0.01 g (3).
Chasmataspidida.--These little-known late Cambrian-mid Devonian marine euchelicerates are characterized by a long postabdomen of nine segments, but share prosomal features with both eurypterids and xiphosurans, rendering their monophyly and affinities uncertain.
Measurement consisted of recording the inter-ocular width (IO), the distance between the inside margins of the horseshoe crab's compound eyes, and the prosomal width (P), which is the distance across the horseshoe crab's carapace.
The prosomal widths of the crabs were measured and recorded.
This specimen is probably either young or of a different sex from the type." The illustration of the prosomal ventral complex seems to indicate a closed gonostome, typical of immature specimens.
(Note that leg measurements were standardized to a common prosomal wet weight; see Table 2.) Among the Monterey Wharf sites, leg length is significantly negatively correlated with flow velocity, with slopes varying from -0.28 to -0.36 depending on the cirrus.
For subsamples of a large catch, 50 crabs greater than 150 mm prosomal width were examined, as well as all small, soft, and shedding crabs.
In Figure 1c, we added a gray reference area that represents the prosomal width and [[delta].sup.15]N values for crabs from Pleasant Bay (1), the most pristine of the three estuaries.