Search results
Results from the WOW.Com Content Network
Gladius, showing measurement of rachis and vane. The gladius (pl.: gladii), or pen, is a hard internal bodypart found in many cephalopods of the superorder Decapodiformes (particularly squids) and in a single extant member of the Octopodiformes, the vampire squid (Vampyroteuthis infernalis). [1]
Bigfin squids are a group of rarely seen cephalopods with a distinctive morphology.They are placed in the genus Magnapinna and family Magnapinnidae. [2] Although the family was described only from larval, paralarval, and juvenile specimens, numerous video observations of much larger squid with similar morphology are assumed to be adult specimens of the same family.
Cephalopod limbs bear numerous suckers along their ventral surface as in octopus, squid and cuttlefish arms and in clusters at the ends of the tentacles (if present), as in squid and cuttlefish. [9] Each sucker is usually circular and bowl-like and has two distinct parts: an outer shallow cavity called an infundibulum and a central hollow ...
In addition, tunics take up only 1% of the squid mantle's wall thickness, whereas the longitudinal muscle fibers take up to 20% of the mantle wall thickness in octopuses. [81] Also because of the rigidity of the tunic, the radial muscles in squid can contract more forcefully. The mantle is not the only place where squids have collagen.
Cephalopods exhibit various dermal structures on their mantles and other parts. These may take the form of conspicuous warts, cushions, papillae or scales, though in many species they are microscopic tubercles. [4] The most elaborate forms are found among the oceanic squid of the order Teuthida. [1] [5]
Ventral view of the viscera of Chtenopteryx sicula showing the position of the ink sac. An ink sac is an anatomical feature that is found in many cephalopod mollusks used to produce the defensive cephalopod ink.
The mantle cavity functions as a respiratory chamber in most mollusks. In bivalves it is usually part of the feeding structure. In some mollusks the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a locomotory organ. The mantle is highly muscular.
An extreme development of the cephalopod fin is seen in the bigfin squid of the family Magnapinnidae. [2] Fins project from the mantle and are often positioned dorsally. In most cephalopods, the fins are restricted to the posterior end of the mantle, but in cuttlefish and some squid they span the mantle's entire length.