Growth and reproduction of the squid Illex coindetii Verany, 1839 in the central Mediterranean Sea

Life span, growth and cost of reproduction of Illex coindetii were examined for the first time in the southern Adriatic Sea, central Mediterranean Sea. Age and growth were investigated through statoliths reading. Cost of reproduction was explored by studying the relative investment between somatic and gonad growth. The life span of I. coindetii was less than nine months in both sexes. Females (128-234 days) showed longer life span than males (124-178 days). In both sexes the linear model best described the mantle length-at age data, while the exponential model provided the best fit to the total weight-at-age data. In terms of mantle length, females grew faster than males (average growth rate was 1.33 mm day- 1 in females and 1.00 mm day-1 in males). In terms of total weight, no significant differences were highlighted between growth curves of males and females. Mantle length, total weight, mantle weight and fin weight increased up to the latest maturity stage in both sexes. Immature and maturing individuals showed poorer body condition than mature counterparts in both sexes. Some evidences of a reproductive strategy more similar to a multiple-spawning than to a single-spawning species were found

Some information on the biology of Illex coindetii Verany, 1839 (Cephalopoda, Ommastrephidae) in the South-Western Adriatic Sea (Central Mediterraneam)

Distribution, length frequency structure, sex-ratio, maturity and dorsal mantle length–total weight relationship for Illex coindetii (Verany, 1839) were described for the first time in the South-Western Adriatic Sea (Central Mediterranean). Samples came from six experimental bottom trawl surveys carried out within the framework of the Medits programme from 1997 to 2002. Although specimens have been collected at a wide depth range, I. coindetii concentrates between 50 and 200 m. The population had a smaller squid size and length at first maturity with respect to other Mediterranean and Atlantic regions, probably due to the interaction of some environmental factors (sea temperature and fishing pressure) and the biological characteristics of the species. There was no difference in males/females ratio by year, but there was a general dominance of females over males at larger sizes and of males over females at smaller sizes. The different proportion of juveniles and mature individuals in the catch suggested the possibility of a prolonged spawning season with a spring spawning peak. There was a pronounced sexual dimorphism, females mature at larger mantle length attaining larger size in respect of males. Length–weight relationship revealed a difference between sexes in maturing and mature individuals only, with males resulting heavier and more robust than females at the same size. There were no differences in body proportions between unsexed and immature individuals of both sexes, which were considerably slimmer than maturing and mature counterparts

A ‘‘Traffic’’ Light approach for the assessment of the Broadtail shortfin squid Illex coindetii Verany, 1839 in the Southern Adriatic Sea (Central Mediterranean

A multi-indicator system and the Traffic Light methodology (TL) to provide the first description of the Illex coindetii (Verany 1839) stock in the GFCM geographical sub-area (GSA) 18 (southern Adriatic Sea; Central Mediterranean) were applied using independent fishery data (‘‘Mediterranean Bottom Trawl Survey’’, ‘‘Medits’’, programme, years 1996–2004). The trajectories of nine population indicators of Frequency of Occurrence (F), Biomass (BI), Density (DI), Recruit Strength (RS), Spawner Strength (SS), Mean Body Weight (MBW), Mantle Length (ML), Mantle Length Excluding Recruits fraction (MLER), Mean mantle Length-Females Length at maturity ratio (MLLm), were analysed using statistical estimators as arithmetic and geometric mean, median, and 75th percentile. The TL methodology was applied to analyse the resulting multiple-indicator panel. Results describe a significant trend of the I. coindetii stock (in number) in the GSA 18 related to a shift within its structure due to a greater proportion of small specimens in the population. Factors that may be contributing to the observed changes are sea temperature, the reduction of possible predators, the recovery of some prey species mostly due to the fishing pressure occurring in the area, and the fast growth and short life span of I. coindetii. In a dynamic system like the Adriatic Sea, the capability to respond quickly to the ‘‘environmental’’ or ‘‘ecosystem’’ changes seem to give I. coindetii an advantage in competition with the long lived finfish species. Accordingly, there is potential to use squid population dynamics as recorders to track environmental and ecological changes, as well as overexploitation. The adopted methodology drew attention to changes occurring within the stock of I. coindetii, and could provide an opportunity for managers to consider action at an early stage. The multi-indicator system and the TL methodology are illustrated as means to follow dynamic changes within squid stock, and to provide usef

Approccio preliminare per lo studio dello stock di vongole (Chamelea gallina, L.) antistante la Torre del Cerrano (TE), Mare Adriatico: una possibile Area Marina Protetta.

The coastal area in the Teramo province (middle Adriatic) is characterized, in productive terms, by the clams (Chamelea gallina) fishing through hydraulic dredges. In such context, the present research has the purpose to constitute an introductory scientific base of a project that could make feasible the institution of a protected marine area, defined as “TORRE DEL CERRANO”. Along 16 Km of marine coast between Vomano and Piomba rivers, samplings have been carried out to evaluate the community benthonic structure, the biometric analysis of molluscs, the clams defence mechanisms and their diseases. These assessments represent a cognitive base of environmental “well-being” through the study of the area general biodiversity and, more specifically, the clam population. About the community benthonic structure, the trend of main structural indexes (Margaleff, Shannon Weaver, Eveness and Pielou) has demonstrated a general spatial reduction in the biodiversity from North to South. The biometric analysis of molluscs has been carried out in three different points; the results have demonstrated the absence of sizes greater than 35 mm and the spatial increase of the average size from North to South. The defence mechanisms of the clams has been evaluated after thermic stress and, through immunoblotting with monoclonal antibody anti-hsp 70 bovine brain, the induction of a Heat Shock Protein (HSP) of approximately 70 Kda has been recorded in the mantle. Furthermore, the production of nitric oxide (NO) and reactive oxygen species (ROS), through nitrite and chemioluminescence assays, respectively, has been assessed in haemocytes of clams stimulated to phagocytize. The results have demonstrated a little increase of NO and an absence of ROS production in the haemocytes during phagocytosis. The histo-pathological examination, instead, has revealed in the clam samples the presence of gregarine oocysts and Rickettsiales-like organisms colonies. The obtained results are directed to set a methodological approach that, through continous monitoring, could unite different parameters to improve the clam resource in a context of environmental protection. [...

Biodiversità dei fondi mobili nell’area costiera di Torre del Cerrano (Abruzzo, Italia).

The biodiversity of the soft bottom in the coastal area from the Vomano river to the Piomba river (Central Adriatic) has been studied. Three sub-areas characterized by different biodiversity levels have been found following latitudinal gradient (North to South)[...

Detecting Anomalies in Marine Data: A Framework for Time Series Analysis

An ensemble framework for the analysis of time series from marine backgrounds is proposed to finally identify and classify anomalies in data time series collected from European Union's Earth Observation Programme Copernicus and Marine-EO project. The framework aims to estimate a prediction model for anomalies detection when new records are explored and then rank the magnitude of the anomalies eventually detected in some biogeochemical parameters of marine and ocean waters, such as chlorophyll-a concentrations, surface temperature profiles and dissolved oxygen