469
25 Robsonella fontaniana
25.1.4 Morphological Characteristics
Ibáñez et al. (2008) provide a description of the moderate-sized octopus. It can be
distinguished from other sympatric octopus species by a dorsal white spot anterior
to the head on fresh and live specimens. The same author reports maximum sizes
of 273 mm total length for males and 209 mm for females, dorsal mantle length
(ML) reaching up to 69 mm in females and 68.8 mm in males, with arms length
accounting for about 70 % of the total length (Fig. 25.1). It has a saccular mantle,
bumpy skin with intraocular papilla, arms with two sets of suckers, third arm hectocotylized in males, enlarged suckers in males, siphon organ in a W shape, ink sac
present, radula with seven teeth by transversal row, marginal plaques present. The
hectocotylus has 47–60 suckers, a small ligula and seven copulatory lamellae.
25.1.5 Reproductive Cycle
A total of 21 different clutches of eggs under the care of females were obtained from
natural subtidal refuges between November 2007 and November 2008 by Uriarte
et al. (2009). The length of the embryonic development period calculated according to Uriarte et al. (2009) indicated that the onset of egg laying had taken place in
September 2007, October 2007, January 2008 and April 2008, suggesting that in the
Fig. 25.1 Robsonella fontaniana. Female octopus with spontaneous clutches observed at Hatchery of Marine Invertebrates of the Universidad Austral de Chile (HIM-UACh). The measuring
slide indicates 1 cm.
25 Robsonella fontaniana
25.1.4 Morphological Characteristics
Ibáñez et al. (2008) provide a description of the moderate-sized octopus. It can be
distinguished from other sympatric octopus species by a dorsal white spot anterior
to the head on fresh and live specimens. The same author reports maximum sizes
of 273 mm total length for males and 209 mm for females, dorsal mantle length
(ML) reaching up to 69 mm in females and 68.8 mm in males, with arms length
accounting for about 70 % of the total length (Fig. 25.1). It has a saccular mantle,
bumpy skin with intraocular papilla, arms with two sets of suckers, third arm hectocotylized in males, enlarged suckers in males, siphon organ in a W shape, ink sac
present, radula with seven teeth by transversal row, marginal plaques present. The
hectocotylus has 47–60 suckers, a small ligula and seven copulatory lamellae.
25.1.5 Reproductive Cycle
A total of 21 different clutches of eggs under the care of females were obtained from
natural subtidal refuges between November 2007 and November 2008 by Uriarte
et al. (2009). The length of the embryonic development period calculated according to Uriarte et al. (2009) indicated that the onset of egg laying had taken place in
September 2007, October 2007, January 2008 and April 2008, suggesting that in the
Fig. 25.1 Robsonella fontaniana. Female octopus with spontaneous clutches observed at Hatchery of Marine Invertebrates of the Universidad Austral de Chile (HIM-UACh). The measuring
slide indicates 1 cm.