Browsing by Author "Brunetti, N.E."

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    Calamares de importancia comercial en Argentina. Biología, distribución, pesquerías y muestreo biológico
    (Mar del Plata : JICA. Japan International Cooperation Agency. Instituto Nacional de Investigación y Desarrollo Pesquero INIDEP, 1999) Brunetti, N.E.; Ivanovic, M.L.; Sakai, M.
    An overview of the available information on the commercially important squid species distributed in the Argentine Sea and adjacent zones is given. It includes the most representative characteristics to identify the species and general information on their biology, distribution and fisheries. A biological sampling designis presented, with particular emphasis on the identification of sexual maturity stages. The world market of the squid resources has considerably risen in the last decades and one of the most important fishery zones is placed in the Southwest Atlantic region (Area 41, FAO), where squid represent 25. of the total landings. Illex argentinus, sustains the second fishery in volume, with landings reaching 612.000 tonnes in 1999. Other species, such as Loligo sanpaulensis, Loligo gahi and Martialia hyadesi, are supporting small domestic fisheries. Also included is the current knowledge on Ommastrephes bartrami and Thysanoteuthis rhombus, cosmopolitan species that sustain important fisheries in other regions, and could be fishery exploitably alternatives here. A special case is that of Moroteuthis ingens, a worldwide particularly abundant species, but whose exploitation has been not developed yet. Finally, the giant squid (Architeuthis sp.)is included, as it started to appear frequently in this region during the last years and its knowledge is of high scientific value.
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    Diet of red squid (Ommastrephes bartramii) in the Southwest Atlantic
    (2004) Ivanovic, M.L.; Brunetti, N.E.
    The diet of red squid (Ommastrephes bartramii) during autumn 2001 and 2002 in the SW Atlantic region off Argentina and Uruguay (33° S-42° S;46° W-55° W) was composed mainly of fish (55-68%), followed by squid (32-37%) and zooplankton (8% only in 2001). Around 60% of the fish eaten was identified as myctophids and corresponded to five genera and seven species, with higher frequency of Hygophum hygomii (24-34%). The identification of squids consumed reached 20% in 2001 and 80% in 2002 and the only species identified was O. bartramii, which implies percentages of cannibalism of 5.6% and 25.8% each year. For the range analyzed, 141-443 mm of mantle length (ML), the consumption of fish and squid did not show any relation to the size of predator. In 2001 the presence of zooplankton wasrestricted to individuals smaller than 300 mm ML. The diversity of diet was low and stomachs with a single type of prey predominated both years 59% in 2001, 92% in 2002
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    Reproductive biology of red squid (Ommastrephes bartramii) in the Southwest Atlantic
    (Mar del Plata : Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Brunetti, N.E.; Ivanovic, M.L.; Aubone, Aníbal; Pascual, L.N.
    Red squid (Ommastrephes bartramii) samples were collected during six exploratory cruises carried out in the Southwest Atlantic region off Argentina and Uruguay (33° S-42° S; 43° W-55° W) during summer-autumn of the period 1997-2002 on board the japanese jigger “Shinko Maru N° 3” under a joint research programme approved by Japan and Argentina. Size ranges of the squids analyzed were 10-40 cm mantle length (ML) for males and 12-49 cm ML for females. Two groups of squids were identified: smaller and larger than 20 cm ML. The group under 20 cm ML was characterized by the presence of immature squids and a sex ratio of around 1:1 in the whole study area. The squids of more than 20 cm ML included from immature to mature individuals. The mean sizes, proportion of mature individuals and proportion of males within this group increased northwards. Mature individuals were captured north of 39°S. The size and weight at 50% maturity were estimated at 30.48 cm ML and 852.95 g body weight (BW) for males and 42.30 cm ML and 2,287.18 g BW for females. The growth in weight of the reproductive system in both sexes was slow until the onset of maturity (males: 27-32 cm LM; females: 37-45 cm LM). The quantitative indices of maturity based on gravimetric measurements of the reproductive system structures showed that in both sexes the reproductive system total weight (RSW) represented less than 1% of BW by the onset of maturity. Then, the growth of the reproductive system accelerated, with RSW reaching 5% of male BW and 8% of female BW by the end of maturity.