Summer squid

Marine cephalopod mollusc with mantle robust, widest at midpoint between anterior end and beginning of fins; tail not sharply pointed. Fin angle moderate, 40° to 50° mostly 45° ; fin width greater than fin length. Head small, short and narrow. Arms relatively short, of about equal length in both sexes; hectocotylized arm (in males) shorter than the opposite ventral arm (IV), its modified portion very short, about 22% of arm length. Colour: reddish-brown to deep purple, more intense on head, arms and dorsal surface of mantle and fins; paler on ventral surfaces; a brilliant yellowish-green tint. Maximum mantle length 31 cm.