This study represents the first to report for arms regeneration and hectocotylus in L.
Hectocotylus regeneration in wild-caught sepiolid squids.
A generic revision of the family Loliginidae (Cephalopoda; Myopsida) based primarily on the comparative morphology of the hectocotylus
Many squid species have a modified arm, the hectocotylus
, for the transfer of spermatophores.
was more than 50% of the length of the hectocotyli in males (Santos & Haimovici 1997b).
maya when he noticed the presence of a hectocotylus
(copulating arm) in animals at an age of 4 months after hatching, when the smallest octopus weighed 10 g BW and the largest weighed 53 g of BW.
a) Male (38 mm ML), ventral view, b) dorsal view, c) hectocotylus
, d) tentacular club; e) Female (52.4 mm ML), ventral view, f) dorsal view, g) sucker from right arm III, h) upper beak, i) lower beak, j) radula, k) funnel valve.
Because squid that implant spermatangia have a long penis and no hectocotylus
, embedding has been suggested to involve the penis in a process by which the spermatophores are perhaps hydraulically forced into the tissue (3, 4).
Measurements included: dorsal mantle length (ML); mantle width (MW); right fin length (RFL); fin width (FW); head length (HL); head width (HW); eye diameter (ED); arm I length (AIL); arm II length (AIIL); arm III length (AIIIL); arm IV length (AIVL); hectocotylus (H); tentacle length (TL); tentacular club length (TCL); funnel width (FuW); and funnel length (FL).
The hectocotylus, is a valuable taxonomic character that can be used to separate species (Brakoniecki, 1986).
To initiate sperm transfer, the muscular penis, which is continuous with the penial diverticulum, propels a stored spermatophore through the funnel to a groove on the ventral margin of the hectocotylus, one of the third arms (usually the right) that is shorter than the opposite arm.
Preliminary analyses found that length variation in the hectocotylus and the unmodified third arm is strongly linked to overall species morphology; to focus this exploration on reproductive characters, arm lengths were not considered.