scholarly journals Feeding and ecomorphology of three clupeoids in the N Aegean Sea

2013 ◽  
Vol 15 (1) ◽  
pp. 9 ◽  
Author(s):  
P. K. KARACHLE ◽  
K. I. STERGIOU
Keyword(s):  
Trophic Level ◽  
Feeding Habits ◽  
Aegean Sea ◽  
Life Cycles ◽  
Mouth Area ◽  
Morphological Features ◽  
Sardina Pilchardus ◽  
Intestine Length ◽  
Sardinella Aurita ◽  
The Individual

The present study examines the feeding habits of anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus) and round sardinella (Sardinella aurita). The results are combined with previously published information on feeding-related morphological features (i.e. mouth area, intestine length and tail area) in order to explore morphological affinities between species and the effect of ecomorphology on their co-existence. These species were mainly zooplanktivorous and no dietary differences were found with sex and season. Anchovy preyed mainly on Crustacea larvae, whereas sardine and round sardinella on Copepoda. In the majority of cases (>90%), the individual fractional trophic level of all species ranged between 3.0 and 3.5, classifying them as omnivores with preference to animals. The feeding-related morphological features differed between anchovy and the two other species, whereas only intestine length differed between sardine and round sardinella. The fact that round sardinella’s diet and morphology show a greater resemblance to those of sardine, further support the hypothesis that is a particulate feeder as sardine. Hence the three species tend to exploit the same food resources differently throughout the year. Thus, they make best use of the environment and its resources, in order to avoid competition and achieve optimum feeding conditions throughout their life cycles

scholarly journals Species diversity and dominancy indexes in Izmir Bay (Aegean Sea) purse seine fishery

2020 ◽  
Vol 37 (4) ◽  
pp. 353-356
Author(s):  
Ahmet Mert Senbahar ◽  
Özlem Güleç ◽  
Zafer Tosunoglu
Keyword(s):  
Dominant Species ◽  
Diversity Index ◽  
Aegean Sea ◽  
Purse Seine ◽  
Total Biomass ◽  
Sardina Pilchardus ◽  
Izmir Bay ◽  
Bony Fishes ◽  
Sardinella Aurita ◽  
Purse Seine Fishery

To determine the diversity index values of species caught by purse seine, all samplings were carried out between September 2, 2017, and April 6, 2018 in Izmir Bay. As a result, a total of 17 fish species (Osteichthyes) belonging to 11 families and also 2 species from invertebrates (Cephalopoda and Arthropoda) were determined. Bony fishes and invertebrates consist of 99.9% and 0.1% of the total biomass, respectively. Sardina pilchardus was the most dominated species that occupied as 80.2% of the overall bony fishes followed by Engraulis encrasicolus (14.6%) and Sardinella aurita (1.5%). Diversity index values of species were found-1.026 by Shannon-Weaver and 0.63 by Simpsons, respectively. The highest dominancy was found for S. pilchardus with 71.1%. Overall final results indicate that the diversity of species in Izmir Bay purse seine fishery is very low and also S. pilchardus is the most over-dominant species.

scholarly journals Retention probability of purse seine grating sieve based on fish morphology

2021 ◽  
Vol 38 (2) ◽  
pp. 173-180
Author(s):  
Zafer Tosunoğlu ◽  
Sinan Mavruk ◽  
Nazlı Kasapoğlu
Keyword(s):  
Simulated Data ◽  
Aegean Sea ◽  
Purse Seine ◽  
Maximum Height ◽  
Sardina Pilchardus ◽  
Maximum Width ◽  
Engraulis Encrasicolus ◽  
Sardinella Aurita ◽  
First Maturity ◽  
Boops Boops

The retention-releasing patterns of the double-grid grating sieve placed on the deck of the purse seiners were revealed for four case species (Sardina pilchardus, Sardinella aurita, Engraulis encrasicolus and Boops boops) using a simulated data predicted from total length (TL) – maximum height (Hmax) and TL – maximum width (Wmax) regressions. To calculate these relationships, samples were collected during commercial purse seine operations between 3 April 2017 and 21 March 2018 in Izmir Bay, Aegean Sea (Turkey). Optimal Bar Spacing (OBS) values corresponding to minimum landing sizes or the length at first maturity were calculated separately for each species. OBS values were found 10.97 mm for sardine (Sardina pilchardus), 11.29 mm for round sardine (Sardinella aurita), 7.78 mm for anchovy (Engraulis encrasicolus) and 17.89 mm for bogue (Boops boops). The bar spacing regulations may constitute a promising management measure to release undersized fish for the purse seine fishery in the Aegean Sea.

Feeding habits and trophic level of the smooth hammerhead shark, Sphyrna zygaena (Carcharhiniformes: Sphyrnidae), off Ecuador

2018 ◽  
Vol 99 (3) ◽  
pp. 673-680 ◽  
Author(s):  
Colombo Estupiñán-Montaño ◽  
Luis Cedeño-Figueroa ◽  
José F. Estupiñán-Ortiz ◽  
Felipe Galván-Magaña ◽  
Alejandro Sandoval-Londoño ◽  
...  
Keyword(s):  
Trophic Level ◽  
Feeding Habits ◽  
Trophic Niche ◽  
Commercial Fishing ◽  
Dosidicus Gigas ◽  
Apex Predators ◽  
Marine Food Webs ◽  
Fishing Vessels ◽  
Marine Food ◽  
Index Of Relative Importance

As apex predators, sharks are known to play an important role in marine food webs. Detailed information on their diet and trophic level is however needed to make clear inferences about their role in the ecosystem. A total of 335 stomachs of smooth hammerhead sharks, Sphyrna zygaena, were obtained from commercial fishing vessels operating in the Ecuadorian Pacific between January and December 2004. A total of 53 prey items were found in the stomachs. According to the Index of Relative Importance (%IRI), cephalopods were the main prey (Dosidicus gigas, Sthenoteuthis oualaniensis, Ancistrocheirus lesueurii and Lolliguncula [Loliolopsis] diomedeae). Sphyrna zygaena was thus confirmed to be a teutophagous species. The estimated trophic level of S. zygaena was between 4.6 and 5.1 (mean ± SD: 4.7 ± 0.16; males: 4.7; females: 4.8). Levin's index (BA) was low (overall: 0.07; males: 0.08; females: 0.09), indicating a narrow trophic niche. We found that sharks <150 cm in total length consumed prey of coastal origin, whereas sharks ≥150 cm foraged in oceanic waters and near the continental shelf. The analyses indicate that S. zygaena is a specialized predator consuming mainly squids.

Memoirs: The Neuro-Muscular Mechanism of the Gill of Pecten

1930 ◽  
Vol s2-73 (291) ◽  
pp. 365-392
Author(s):  
S. B. SETNA
Keyword(s):  
Feeding Habits ◽  
Adductor Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Gill Filaments ◽  
Lateral Extent ◽  
Branchial Nerve ◽  
The Individual ◽  
Stimulation Of

Experimental. 1. The contraction of the adductor-muscle which follows stimulation of the palial nerve is preceded by a marked contraction of the ctenidial axis, so that the gill contracts before the adductor-muscle becomes active. This movement of the ctenidium is abolished if the main branchial nerve is cut near its origin. 2. The gills of Pecten possess a neuromuscular mechanism which is to some extent independent of the rest of the body, so that excised gills when stimulated react in the same way as an attached gill. 3. The lamellae of the gill possess two distinct types of movement. (a) When the surface of the gill is stimulated by contact with a glass rod or by carmine particles, the frontal surfaces of the two lamellae approach each other; the movement very often being executed by the lamella which is not actually being stimulated. The lateral extent of these movements (concertina movements) is roughly proportional to the intensity of the stimulus. Such movements normally appear to transfer the bulk of the material on to the mantle. Separation of the main branchial nerve abolishes these movements. (b) Each principal filament is capable of moving the ordinary filaments to which it is attached. This movement (flapping movement) is due to the movements of the interfilamentar junctions which alternatively move up and down at right angles to their length. This motion is independent of the branchial nerve and can be produced by direct stimulation of very tiny pieces of the individual filaments. 4. The significance of gill movements to feeding habits is discussed. The course of food particles depends on the nature of the stimuli affecting the gill. Histological. 5. The ctenidial axis and the principal filaments have a stratum of anastomosing nerve-cells which appear to form a true nerve-net comparable to that of the mantle. 6. The gill receives nerve-fibres from two sources, the brain and the visceral ganglion. The subsidiary branchial nerve is a structure hitherto unknown in the molluscan gill; so far its function is unknown. Each gill has four main longitudinal nerve-trunks. 7. The osphradium of the gill has a much more extensive distribution than has hitherto been supposed. 8. Two sets of muscles exist at the base of the gill-filaments, and these are responsible for movements of the lamellae. The muscle-fibres are non-striated. 9. The principal filaments are connected to the ordinary filaments by processes containing true muscle-cells, and by these cells movements of the filaments are effected.

Biomass models for three species with different growth forms and geographic distribution in the Brazilian Atlantic forest

2021 ◽  
pp. 1-13
Author(s):  
Heitor Felippe Uller ◽  
Laio Zimermann Oliveira ◽  
Aline Renata Klitzke ◽  
Joberto Veloso de Freitas ◽  
Alexander Christian Vibrans
Keyword(s):  
Atlantic Forest ◽  
Geographic Distribution ◽  
Morphological Features ◽  
Brazilian Atlantic Forest ◽  
Growth Forms ◽  
Individual Level ◽  
Generic Models ◽  
The Individual ◽  
Species Specific ◽  
Individual Trees

Allometric models embedding independent variables such as diameter at breast height (d) and total height (h) are useful tools to predict the biomass of individual trees. Models for tropical forests are often constructed based on datasets composed of species with different morphological features and architectural models. It is reasonable to expect, however, that species-specific models may reduce uncertainties in biomass predictions, especially for palms, tree ferns, and trees with peculiar morphological features, such as stilt roots and hollow trunks. In this sense, three species with wide geographical distribution in the Brazilian Atlantic Forest were sampled, namely Euterpe edulis Mart., Cyathea delgadii Sternb., and Cecropia glaziovii Snethl., with the aim to (i) quantify their aboveground biomass (AGB), (ii) evaluate the AGB distribution in different plant compartments, (iii) fit species-specific models for predicting AGB at the individual level, and (iv) assess the performance of specific and generic models available in the literature to predict the AGB of individuals of these species. The compartment stem represented, on average, ∼74% of the total AGB of E. edulis individuals; in turn, the caudex compartment of C. delgadii represented, on average, ∼87% of the total AGB, while the trunk compartment of C. glaziovii represented, on average, ∼74%. Among the fitted models, the power model [Formula: see text] showed the best performance for E. edulis and C. delgadii. In turn, the asymptotic logistic model [Formula: see text], where dc is the diameter above the upper stilt root, presented the best performance for C. glaziovii. The variable h appeared as the most important predictor of AGB of E. edulis and C. delgadii; in contrast, the stem and caudex mean basic specific gravities were not suitable predictors. The fitted species-specific models outperformed the specific and generic models selected from the literature. They may, therefore, contribute to the reduction of uncertainties in AGB estimates. In addition, the results support evidence that specific models may be necessary for species with different growth forms and (or) peculiar morphological features, especially those with great abundance and wide geographic distribution.

scholarly journals Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil

1998 ◽  
Vol 41 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Paulo de Tarso C. Chaves ◽  
Ana Lúcia Vendel
Keyword(s):  
Feeding Behaviour ◽  
Food Item ◽  
Feeding Habits ◽  
Fish Populations ◽  
The Individual ◽  
High Level ◽  
Individual Size

Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.

scholarly journals Analysis of the Energy Balance of Constructions Based on Wood during Their Use in Connection with CO2 Emissions

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4843
Author(s):  
Jozef Švajlenka ◽  
Mária Kozlovská
Keyword(s):  
Energy Demand ◽  
Average Energy ◽  
Primary Objective ◽  
Life Cycles ◽  
Individual Characteristics ◽  
Co2 Production ◽  
Use Phase ◽  
The Individual ◽  
Medium Type ◽  
Heating Medium

In the construction industry, it is the material production phase and the use phase of buildings’ life cycles that represent the greatest environmental burden. The presented research focused on wood constructions during their use phase. The primary objective of the research was to determine the amount of CO2 produced during the operation of specific wood constructions in connection with the energy demand for their heating. A correlation analysis of selected parameters revealed a statistically significant correlation between heating medium type and energy demand for heating (p = −0.5773) and between heating medium type and amount of CO2 produced (p = 0.4796). A more detailed analysis showed that, in terms of the average energy demand for heating, the column constructions were the most efficient among the compared construction systems, regardless of the energy standard. Similar findings were obtained for annual CO2 production in connection with the average energy demand for heating. The only difference was that the panel and log constructions exhibited almost identical parameters, which came as a surprise to some extent. The column constructions turned out to be the most efficient again, regardless of their energy standard. The analysis that focused on the heating medium type revealed statistically significant differences among the heating medium types in energy demand for heating (p < 0.0001). The constructions that used electricity for heating were the most energy-efficient. When the individual characteristics of the different heating media in relation to CO2 production were taken into account, the constructions that were heated using biomass were the least polluting. The constructions heated using electricity and gas showed a significantly greater deviation.

scholarly journals Feeding ecology of stream-dwelling fishes from a coastal stream in the Southeast of Brazil

2007 ◽  
Vol 50 (4) ◽  
pp. 627-635 ◽  
Author(s):  
Rosana Mazzoni ◽  
Leandro Damião Soares da Costa
Keyword(s):  
Feeding Habits ◽  
Resource Exploitation ◽  
Ontogenetic Changes ◽  
Size Category ◽  
Food Category ◽  
Geophagus Brasiliensis ◽  
Intestine Length ◽  
The Relationship ◽  
Animal Category ◽  
Mimagoniates Microlepis

The relationship between ontogenetic variation of intestine length and feeding habits of five stream-dwelling fish species from the Ubatiba River were investigated. Analysed data were based on two size categories (juveniles and adults) and two food categories (animal and vegetal). Diet composition of each size category revealed that Astyanax janeiroensis and Geophagus brasiliensis changed food preference throughout ontogeny and switched from omnivorous/carnivorous to omnivorous/herbivorous and from omnivorous/carnivorous to omnivorous, respectively. These changes were followed by ontogenetic changes in the Intestinal Coefficient (IC). No ontogenetic differences were registered for IC and food categories consumed by Hoplias malabaricus but significant differences in the size of consumed preys as well as positive correlation between fish size (predator) and prey size was observed. Food items (within animal category) consumed by the adult Pimelodella lateristriga were mainly based on allochthonous arthropods whereas juvenile individuals fed with the same intensity on allochthonous and autochthonous arthropods; both juveniles and adult individuals of Mimagoniates microlepis were mainly allochthonous feeders. Mean IC values of Pimelodella lateristriga and Mimagoniates microlepis did not change along body growth. Although changes in food category consumption were not common among all the studied species, changes in the resource exploitation strategy was a rule among them, except for Mimagoniates microlepis.

Late Cretaceous (Maastrichtian) crocodyliforms from north-eastern Iberia: a first attempt to explain the crocodyliform diversity based on tooth qualitative traits

2019 ◽  
Vol 189 (2) ◽  
pp. 584-617 ◽  
Author(s):  
Alejandro Blanco ◽  
Eduardo Puértolas-Pascual ◽  
Josep Marmi ◽  
Blanca Moncunill-Solé ◽  
Sergio Llácer ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Feeding Habits ◽  
Morphological Features ◽  
Taxonomic Significance ◽  
Environmental Preferences ◽  
Qualitative Traits ◽  
North Eastern

Abstract During recent years, knowledge about crocodyliform diversity of the uppermost Cretaceous from Europe has been substantially improved. Palaeontological efforts have also been focused on microvertebrate diversity and its palaeoecological implications. Isolated crocodylomorph teeth are, by far, one of the most frequently recovered elements in microvertebrate samples. In the present paper, morphological features of crocodylomorph teeth collected throughout the complete Maastrichtian series of the southern Pyrenean basin (north-eastern Spain), together with several mandibular remains, are described and analysed. Teeth were grouped in morphotypes and their taxonomic significance is discussed. The results highlight a diverse crocodylomorph assemblage in this area throughout the Maastrichtian. In addition, feeding habits and environmental preferences are inferred for the identified taxa according to dental features, occurrences and taphonomy.

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