1,721,113 research outputs found
Osservazioni sulla riproduzione di Aristeus antennatus e Aristaeomorpha foliacea (Crustacea, Decapoda) nel compartimento marittimo di Gallipoli (Mar Ionio)
No full textTwo traditional Reference Points based on the yield per recruit model, corrected by ecological and economic weights
No full textExperimental data on growth, mortality and reproduction of Ostrea edulis (L., 1758) in a semi-enclosed basin of the Mediterranean Sea
No full textBiometry, growth, survival and mortality rates as well as reproduction of O. edulis have been evaluated in the Taranto Sea, a semi-enclosed basin of the North-Western Ionian Sea (Mediterranean Sea). A crossed experimental design with 3 factors (container, depth and stocking density) was defined to investigate their effect on the sizes, growth performance, survival and mortality rates. Moreover, the reproduction was studied to better understand the life cycle of the species in the basin. The investigated experimental conditions caused significantdifferences inbothsizechangesandgrowthparameters. In particular, the density was the main factor influencing both biometry and growth. The oysters cultivated at low density showed L∞ (155.46±46.38mmDVL), k (0.42±0.25 year−1) andΦ′ (2.00) values significantly higher than those reared at high density L∞ (134.28±36.13 mm DVL), k (0.35±0.22 year−1) and Φ′ (1.80). The winter point (WP) occurred during winter and the strength of the seasonal oscillation (C) ranged between 0.10 and 0.37. No significant differences between the experimental rearing conditions were observed in either survival (S) or mortality (Z) rates. Oysters reared at low and high density showed mean S values equal to 0.88±0.03 and 0.89± 0.03, respectively as well as mean Z values equal to 0.13±0.03 and 0.12±0.04. Maturation of gonads occurred continuously during the year showing a slackening during summer when the highest temperatures were recorded in the water column. In addition, the highest percentages of fluent gonads were observed during winter. Histological analysis confirmed the macroscopic observation of gonads. In particular, gamete differentiation was observed during late autumn and early winter. An inverse correlation between the condition index and themean temperature in the water columnwas observed throughout the study period. The present results indicate an optimal crop age of about 2 years, corresponding to the commercial size of 8–9 cmdorsal–ventral length and weight of 55–60 g
Esperimenti di selettività della rete a strascico relativi alla pesca di Aristeus antennatus ed Aristaeomorpha foliacea nella marineria di Gallipoli (Mar Ionio)
No full textAspetti riproduttivi di Ostrea edulis (L., 1758) (Bivalvia: Ostreacea) nel Mar Grande di Taranto (Mar Ionio Settentrionale)
No full textThe reproductive features of O. edulis were investigated collecting monthly samples from a breeding population in the Mar Grande of Taranto (Northern Ionian Sea). A total of 240 gonads were observed. Macroscopic observations were compared with histological preparations. Mature eggs and sperms were observed throughout the year. Spawning and incubation of larvae occur during spring and summer with a lowering during July and August, when the highest temperatures were recorded into the sea
Phenology of the alien seaweed Grateloupia turuturu population in the Mar Piccolo of Taranto.
No full textOccurrence of the basking shark Cetorhinus maximus (Gunnerus, 1765) (Lamniformes: Cetorhinidae) in the central-eastern Mediterranean Sea
No full textThe presence of the basking shark Cetorhinus maximus (Lamniformes: Cetorhinidae) in the central-eastern Mediterranean
Sea has been documented by means of 15 sightings and two accidental catches which occurred from February 2011 to
January 2014 in the northwestern Ionian and southern Adriatic Sea. Specimens were observed exhibiting typical feeding
behaviour, swimming slowly on the surface, during each sighting. In the case of the accidental catches, the basking shark
specimens were released still alive by local fishermen. The observed specimens measured between 4 and 9 m in total length
(TL). The sightings could be due to an increase in effort in the monitoring of the species occurring in the Mediterranean Sea
as a consequence of a rise interest in the conservation of threatened species
Invasive or not? The case of Grateloupia turuturu (Rhodophyta, Halymeniales) in the Northern Ionian Sea (Mediterranean Sea)
No full textIt has been predicted that Grateloupia turuturu, native of the cold-temperate waters of Japan, is one of the most invasive marine species considered as a threat to global marine biodiversity. However, few studies have been carried out to assess the extent of its spread worldwide. Its seasonal dynamics in the Mar Piccolo of Taranto, a transitional water system in the Northern Ionian Sea, were observed for ten years. Systematic monthly observations were carried out from 2008 to 2018. The length of thalli and density were measured alongside the seawater temperature. Data were processed by means of non-parametric statistical analyses. No invasive behavior was detected for G. turuturu. It seems well established in the Mar Piccolo even though its population is limited to the station of first detection. However, due to its shown preference for plastic substrate, it could become a vector of another urgent threat, that is plastic pollution
First record of dwarf flathead Elates ransonnetii (Platycephalidae) in the Mediterranean Sea (North-western Ionian Sea)
No full textPremier signalement du platycéphale Elates ranson -
netii en mer Méditerranée (mer Ionienne nord-occidentale).
Un Elates ransonnetii ( S t e i n d a c h n e r, 1876) a été capturé, en
octobre 2005, en mer Méditerranée le long de la côte italienne (mer
Ionienne), dans le golfe de Tarente. L’individu a été capturé par 20
m de profondeur sur un fond sableux. Il s’agit d’un mâle de 147
mm de longueur totale, sexuellement mature
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