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(invertebrate zoology)
The body division comprising the united head and thorax of arachnids and higher crustaceans.



that part of the body of arthropods formed as a result of the fusion of the cephalic and thoracic segments.

The cephalothorax is characteristic of higher crustaceans and chelicerate arthropods (Arachnida, Xiphosura, and the extinct paleozoic Eurypteridae). Among the crustaceans, the cephalothorax is formed in Decapoda by the fusion of six cephalic and seven thoracic segments. In Chelicerata it consists of the six front segments of the body (which usually bear the appendages), to which a seventh (pregenital) segment is sometimes attached.

References in periodicals archive ?
Once the spider is on the filter paper, a glass stirring rod is inserted through the longitudinal slit and pushed down onto the spider in the area between the cephalothorax and the abdomen.
The ventral surface of the cephalothorax possesses 10 leg sockets from which extended the eight walking legs (pereiopods) and two chelae.
Percentage of growth of the width and length of the cephalothorax (cph) and the femur (F) and tibia (T) of legs I and IV between successive stages (first row).
Table 1 Number of lobster stomachs sampled by classes of cephalothorax length (CL, in mm).
Filters were held on the lobster by wrapping a rubber band around the cephalothorax of the lobster between the second and third pereiopods.
Eight pairs of submarginal setae (sms): 4 pairs each on cephalothorax and abdomen.
To measure flux emanating in situ from living cuticle a form-fit Tygon Tubing observational arena was glued to the cephalothorax of lobsters using Krazy-Glue Gel (Fig.
In summary, on the basis of the features, such as the composition of the cephalothorax either from the associated plates or tesserae (Astraspis, Tesseraspis), or discrete but interlocking tesserae (Aserotaspis, Lepidaspis, ?
Instar D has cephalothorax and abdomen in the same plane, pigments present, eyes present, absence of tarsal scopulae and claw tufts, slow locomotion.
BL = total body length: length of head, thorax and abdomen for insects; length of head and body trunk in millipedes; length of cephalothorax and abdomen for other arthropods.