arm was less susceptible to injury in comparison to other arms (Fig.
ocellatus belong to the short wrist type octopus and the hectocotylized
arms are similar with each other while the hectocotylized
arms of O.
All these octopuses are very similar based on morphology, which makes their taxonomic identification confused and problematic; however, both of the aforementioned authors reported that a few morphological traits (e.g., hectocotylized arm sucker count) are useful in making discriminations within the O.
The sucker count of the hectocotylized arm (third right arm), which has been considered an important diagnostic character for species distinction within the O.
The measurements (in mm) and indices used in the work are as defined by Roper & Voss (1983): mantle length (ML); mantle width index (MWI); fin length index (FLI); fin width index (FWI); and hectocotylized arm length index (HcLI).
Hectocotylized arm without crest: suckers reduced, sucker stalks elongated to form papillae on either dorsal or both dorsal and ventral rows.
The sex of each animal was determined by the presence (male) or absence (female) of the hectocotylized
right third arm.
Simultaneous with this rotation, the hectocotylized
arm (left 4th arm) began moving back toward the funnel, and the right 4th arm moved toward the buccal region of the female (Fig.
Measurements and indices used in the work are as defined by Roper & Voss (1983): mantle length (ML); mantle width index (MWI); fin length index (FLI); fin width index (FWI); index arm I length (AILI); index arm II length (AILII); index arm III length (AILIII); index arm IV length (AILIV) and hectocotylized
arm length index (HcLI) (Tabla 1).
For each individual, sex was determined by checking the presence of the left arm IV hectocotylized
(modified arm) typical for males (Richard 1967).
The species is characterized by: its small size at maturity (mantle lengths of males 20.8 to 29.6 mm and females 20.6 to 38.8 mm); the lack of buccal suckers; and it is the only myopsid squid in which the right ventral arm is hectocotylized
instead of the left (Figs.
All specimens were kept frozen till transferred to the laboratory where triplicate samples of mantle tissue were collected for the biochemical analysis after determining the sex by checking the presence of the left arm IV hectocotylized
(modified arm) typical of males (Richard 1967).