Reproductive aspects, eggs and paralarvae ofRobsonella fontanianus(d'Orbigny, 1834)

Exotic Amphipods in Aquaculture Systems: Presence and Potential Use

“…R. fontaniana is a small octopus, abundant in southern Chile; its distribution ranges from 5 • S on the Pacific Coast, to 42 • S on the Atlantic coast (Ré, 1998). The diet of octopus paralarvae (Iglesias et al, 2004;Carrasco et al, 2006;González et al, 2008;Villanueva & Norman, 2008;Uriarte et al, 2010) and adults (Pérez et al, 2006;Ibañez et al, 2009) is based on crustaceans.…”

New records of early life stages of cephalopods in the Chiloe Interior Sea

“…From the other two, E. megalocyathus is the only large octopod (~1 m total length [TL]) recorded in this area (Osorio et al, 2006;Häussermann & Försterra, 2009), with paralarvae around 8 mm DML and a planktonicbenthic period of dispersal (Ortiz et al, 2006), which could explain the large size of the paralarvae collected. By contrast, for R. fontaniana smaller adult sizes (28 cm TL), smaller hatchling sizes (~4.0 mm TL), extended planktonic periods (~72 days) and large benthic stage size (~11 mm TL) have been recorded (González et al, 2008;Ortiz & Ré, 2010;Uriarte et al, 2010), supporting the identity of the small paralarvae collected. A skin film covering the body of the paralarvae has been reported in several species of octopuses, including E. megalocyathus (see Villanueva & Norman, 2008); however, it was not detected by Ortiz & Ré (2010) in R. fontaniana hatchlings.…”

“…O. mimus, R. fontaniana, E. megalocyathus) and squids (e.g. D. gigas, L. gahi) (Warnke, 1999;Guerra et al, 2001;Castro et al, 2002;Ortiz et al, 2006;González et al, 2008;Staaf et al, 2008;Ortiz & Ré 2010;Uriarte et al, 2010), detailed information on morphological patterns of hatchlings and juveniles has not previously been described. Although the abundance of young cephalopods in our samples seems to be low, similar values have been previously recorded in this geographic area by Vega et al (2000) and Balbontín et al (2004).…”

“…Comparisons among laboratory reared paralarvae of the three most common coastal octopuses from Chilean waters: O. mimus, R. fontaniana and E. megalocyathus [DML (1.69 vs 3.18 vs 8.38), number of suckers (3 vs 4-5 vs 16-27), number of visceral chromatophores (6-8 vs 19-33 vs 100-210)] (Warnke, 1999;Castro et al, 2002;Ortiz et al, 2006;González et al, 2008;Ortiz & Ré, 2010;Uriarte et al, 2010), in addition with the geographic distribution of adult specimens, allowed us to determine the taxonomic identification of the paralarvae collected. From the three above named species, O. mimus is the only one that does not occur in southern Chile (Vega et al, 2001;Ibáñez et al, 2009;Vega, 2009).…”

“…Samples were preserved in 5% formalin in sea water solution until further examination. Each individual was identified to the lowest taxonomic level by comparison with descriptions available in the literature (Sweeney et al, 1992;Ortiz et al, 2006;Bolstad 2008;González et al, 2008;Ortiz & Ré, 2010;Uriarte et al, 2010) using standardized morphological characters, including dorsal mantle length (DML, mm), number and distribution of suckers (S), tentacular club (TC) and chromatophore patterns. Abundance of paralarvae was expressed as ind 1000 m -3 and their spatial distribution were plotted in a map of the area provided by the Chilean Army.…”