Anatomical and physiological factors affecting the swim-bladder cross-section of the sardine <i>Sardina pilchardus</i>

Machias, Athanassios; Τσιμενίδης, Ν.

doi:10.1139/f95-188

Cited by 9 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The amounts of mesenteric fat and lipid content in the tissue were in opposite relation to the sardine sexual cycle, which had been reported earlier but only in part for sardine from the Adriatic Sea and from Greek waters (Krvaric´and Muzˇinic´, 1950;Machias and Tsimenides, 1996). The results provide evidence of lipid reserves in fishes; this evaluation is considered important for population bioenergetics modelling, but is also of high practical value for the sardine processing industry.…”

Section: Discussionsupporting

confidence: 59%

Comparison of mesenteric and tissue fat content in relation to sexual cycle of the sardine,Sardina pilchardus(Walb., 1792), in the eastern Middle Adriatic fishery grounds (Croatia)

Mustać

Sinovčić

2009

Journal of Applied Ichthyology

View full text Add to dashboard Cite

The study objective was to analyse Sardina pilchardus (Walb., 1792) for mesenteric fat, which is easier to evaluate than the muscle lipid, for comparisons thereof with the sexual cycle and condition of the examined specimens. Fat reserves, moisture and the sexual cycle of sardines were studied from monthly random samples of purse seine catches from March 2004 to February 2005. A total of 1209 specimens were collected (668 males; 541 females). Total length and mass ranged from 13.0 to 19.0 cm and from 16.7 to 51.5 g, respectively. Lipid analyses in muscle tissues were done using the Soxhlet method. An inverse relation between fat content and the sexual cycle was established. Greatest fat quantities were observed in August (72%) during the gonadal resting phase; lowest values were noted in winter, and in spring during the spawning period peak. Moisture content and sexual cycle were positively correlated (r = 0.7913). Total lipids in sardine tissues were higher in females than in males; however, the moisture content was higher in males than in females.

show abstract

Section: Discussionsupporting

confidence: 59%

Comparison of mesenteric and tissue fat content in relation to sexual cycle of the sardine,Sardina pilchardus(Walb., 1792), in the eastern Middle Adriatic fishery grounds (Croatia)

Mustać

Sinovčić

2009

Journal of Applied Ichthyology

View full text Add to dashboard Cite

show abstract

“…In future work, more data on swimbladder tilt angle (θsb_tilt) should be collected to verify the TS difference between S. pilchardus and S. aurita, as the present study applied this value from references [16,17].…”

Section: Discussionmentioning

confidence: 99%

“…Tsimenides [16] and 10° for S. aurita after Whitehead and Blaxter [17]. After TS estimation for θfish from -90°…”

Section: Collection Of Fish Samples and Swimbladder Observationsmentioning

confidence: 99%

See 1 more Smart Citation

Estimation of target strength of Sardina pilchardus and Sardinella aurita by theoretical approach

et al. 2016

View full text Add to dashboard Cite

The target strength (TS) patterns of Sardina pilchardus and Sardinella aurita at 38 and 120 kHz were estimated by a prolate-spheroid model, using measurements of swimbladder length and width. The ratio of swimbladder length to total length (TL) was similar in both species, however the ratio of swimbladder width to TL was smaller and more variable for S. aurita. Assuming a normal distribution of fish swimming orientation angle (θfish) with mean ± standard deviation (SD) of 0 ± 10°, the normalized (by TL) average TS (b20) was estimated to be -64.0 dB (38 kHz) and -65.2 dB (120 kHz) for S. pilchardus, and -66.2 dB (38 kHz) and -67.2 dB (120 kHz) for S. aurita. Compared with currently applied b20 values at 38 kHz, our results under four different θfish assumptions (0 ± 10°, 0 ± 15°, -5 ± 10°, and -5 ± 15°) were 6-9 dB higher for S. pilchardus and 5-7 dB higher for S. aurita. This suggests four-to eightfold overestimation risk for S. pilchardus and three-to fivefold overestimation risk for S. aurita when using the currently applied b20 values.Keywords Sardina pilchardus·Sardinella aurita·Target strength·Theoretical approach·Prolate spheroid model ✉Tadanori Fujino

show abstract

“…This is related to the high plasticity observed in fish schools (Misund, 1993) affected by environmental, behavioural, ontogenetic and physiological traits (e.g. Machias & Tsimenides, 1996;Massé et al, 1996;Nøttestad et al, 1996;Tsagarakis et al, 2012b). Nevertheless some general patterns that remain more stable per species can be identified, e.g.…”

Section: Discussionmentioning

confidence: 99%

Species identification of small pelagic fish schools by means of hydroacoustics in the Eastern Mediterranean Sea

et al. 2015

View full text Add to dashboard Cite

Reliable biomass estimates by means of hydroacoustics largely depend on the correct identification of acoustic targets. Data collected during five summer acoustic surveys (2004)(2005)(2006)(2007)(2008) in the North Aegean Sea (Greece) were analyzed to explore effective discrimination of small pelagic fish schools according to the species they belong. Discriminant Function Analyses (DFA) using bathymetric, energetic and morphometric school descriptors as explanatory variables were applied per research cruise as well as to pooled data from all surveys. Results revealed that the schools can be successfully classified into the five species considered (anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, blue whiting Micromessistius poutassou, and Atlantic mackerel Scomber scombrus). The percentage of correct classifications in terms of number of schools was higher in the analyses of the annual cruises (75.6%-95.36%) than in the analysis of pooled data (≈72%). This is because of (i) the lower number of species, as well as (ii) the reduced intraspecific variability, occurring in each separate cruise. Significant differences were detected among school descriptors for the different species, revealing discrete aspects of schooling behaviour for each species. The benefit of the specific approach is that the classification functions of the DFAs can be used to classify a larger set of schools, which has not been possible to assign to specific species. Overall the approach constitutes an objective, more automated and less time consuming procedure for the analysis of acoustic data and can contribute to the improvement of biomass estimates in the area.

show abstract

Anatomical and physiological factors affecting the swim-bladder cross-section of the sardine Sardina pilchardus

Cited by 9 publications

References 13 publications

Comparison of mesenteric and tissue fat content in relation to sexual cycle of the sardine,Sardina pilchardus(Walb., 1792), in the eastern Middle Adriatic fishery grounds (Croatia)

Comparison of mesenteric and tissue fat content in relation to sexual cycle of the sardine,Sardina pilchardus(Walb., 1792), in the eastern Middle Adriatic fishery grounds (Croatia)

Estimation of target strength of Sardina pilchardus and Sardinella aurita by theoretical approach

Species identification of small pelagic fish schools by means of hydroacoustics in the Eastern Mediterranean Sea

Contact Info

Product

Resources

About