scholarly journals The effect of abiotic and biotic factors on the importance of macroplankton in the diet of Northeast Arctic cod in recent years

2005 ◽  
Vol 62 (7) ◽  
pp. 1463-1474 ◽  
Author(s):  
E.L. Orlova ◽  
A.V. Dolgov ◽  
G.B. Rudneva ◽  
V.N. Nesterova

AbstractUsing cod feeding data, this paper considers the distribution and abundance of macroplankton from different ecological groups (euphausiids and hyperiids) and the variability in their consumption by cod over a period of years during which different water mass temperatures were observed. These years were also characterized by variable abundance of capelin, cod's main food source. Differences in intensity and duration of cod consumption of euphausiids and hyperiids species are shown, depending on their abundance, temperature conditions, cod distribution, and the supply of capelin for cod. This paper discusses the energetics of consuming different types of prey and the role euphausiids play in the energy balance of cod. The low fat content of cod is sometimes associated with feeding on postspawning euphausiids in summer and autumn.

2020 ◽  
Vol 84 (4) ◽  
pp. 463-475
Author(s):  
Josep-Maria Gili ◽  
Begoña Vendrell-Simón ◽  
Wolf Arntz ◽  
Francesc Sabater ◽  
Joandomènec Ros

Benthic communities depend on receiving much of their food from the water column. While sinking, particles are transformed in a discontinuous process and are temporally retained in transitional physical structures, which act as boundaries and contribute to their further transformation. Motile organisms are well-acquainted with boundaries. The number, width and placement of boundaries are related to the degree of particle degradation or transformation. Progressively deepening within each boundary, particles are degraded according to their residence time in the discontinuity and the activity of the organisms temporarily inhabiting that boundary. Finally, particles reach the seafloor and represent the main food source for benthic organisms; the quality and quantity of this food have a strong impact on the development of benthic communities. However, benthic communities not only play the role of a sink of matter: they act as an active boundary comparable to other oceanic boundaries, in accordance with the boundary concept proposed by the ecologist Ramon Margalef.


Author(s):  
Francesca Biandolino ◽  
Ermelinda Prato

Lipid and fatty acid composition in Gammarus aequicauda from Mar Piccolo (Ionian Sea, southern Italy) were studied during the spring months. Simultaneously, samples of the macroalgae Chaetomorpha linum were also collected from the same area. During these months Chaetomorpha linum was the main food source of Gammarus aequicauda. The main lipid classes were phospholipids (PL) and triacylglycerols (TG) both in Gammarus aequicauda and in Chaetomorpha linum with similar concentrations. But PL was the main lipid class in Gammarus aequicauda and TG in Chaetomorpha linum. On average unsaturated fatty acids represent the preponderant part in both G. aequicauda and C. linum. Gammarus aequicauda had a higher level in monounsaturated fatty acids (MUFA), on the contrary polyunsaturated fatty acids (PUFA) were the dominant unsaturated fatty acids in C. linum. Both were characterized by high levels of 18:0, 18:1(n-9), 20:5(n-3) and 20:4(n-6), in particular C. linum had a high proportion of 14:0 and the ratio of 18:1n 9/18:1n 7 was high.


2015 ◽  
Vol 17 (1) ◽  
pp. 170 ◽  
Author(s):  
A. TERRÓN-SIGLERA ◽  
D. LEÓN-MUEZ ◽  
P. PEÑALVER-DUQUE ◽  
F. ESPINOSA TORRE

The endangered and Mediterranean endemic orange coral (Astroides calycularis) hosts an important macrofaunal assemblage. The gut contents of the main peracarids associated with the orange coral were analysed. In total 161 specimens belonging to 11 species and 9 families were examined on the southern coast of the Iberian Peninsula. The gut content study was carried out introducing the specimens of each species in Hertwig’s liquid. The analysis revealed that the peracarid species associated with A. calycularis had different feeding strategies and their main food source was detritus. The results highlight that peracarids may depend on the host and the detritus that the coral produces.


Author(s):  
Ricardo Antonio Ayub

Abstract Flavonoids occur naturally and are derived from the phenylpropanoid pathway. There is growing evidence of the preventive and protective roles of anthocyanins against a wide range of pathologies, including different types of cancer and metabolic diseases. However, most red fruits available to consumers typically contain only small amounts of anthocyanins, mainly limited to the epidermis of plant organs. Therefore, we reviewed the current literature on the biosynthesis of anthocyanins in berries, including the structural and regulatory genes involved in the differential pigmentation patterns of plant structures, as well as management and cultural treatments. Also, the genetic regulation of flavonoid biosynthesis in different red fruits is explored to observe and create strategies to increase biosynthesis and anthocyanin accumulation. It is concluded that the regulation, transport and accumulation of flavonoids varies markedly between species, and is influenced by abiotic and biotic factors.


2019 ◽  
Author(s):  
Brandon K. B. Seah ◽  
Chakkiath Paul Antony ◽  
Bruno Huettel ◽  
Jan Zarzycki ◽  
Lennart Schada von Borzyskowski ◽  
...  

AbstractSince the discovery of symbioses between sulfur-oxidizing (thiotrophic) bacteria and invertebrates at hydrothermal vents over 40 years ago, it has been assumed that autotrophic fixation of CO2by the symbionts drives these nutritional associations. In this study, we investigatedCandidatusKentron, the clade of symbionts hosted byKentrophoros, a diverse genus of ciliates which are found in marine coastal sediments around the world. Despite being the main food source for their hosts, Kentron lack the key canonical genes for any of the known pathways for autotrophic fixation, and have a carbon stable isotope fingerprint unlike other thiotrophic symbionts from similar habitats. Our genomic and transcriptomic analyses instead found metabolic features consistent with growth on organic carbon, especially organic and amino acids, for which they have abundant uptake transporters. All known thiotrophic symbionts have converged on using reduced sulfur to generate energy lithotrophically, but they are diverse in their carbon sources. Some clades are obligate autotrophs, while many are mixotrophs that can supplement autotrophic carbon fixation with heterotrophic capabilities similar to those in Kentron. We have shown that Kentron are the only thiotrophic symbionts that appear to be entirely heterotrophic, unlike all other thiotrophic symbionts studied to date, which possess either the Calvin-Benson-Bassham or reverse tricarboxylic acid cycles for autotrophy.Significance StatementMany animals and protists depend on symbiotic sulfur-oxidizing bacteria as their main food source. These bacteria use energy from oxidizing inorganic sulfur compounds to make biomass autotrophically from CO2, serving as primary producers for their hosts. Here we describe apparently non-autotrophic sulfur symbionts called Kentron, associated with marine ciliates. They lack genes for known autotrophic pathways, and have a carbon stable isotope fingerprint heavier than other symbionts from similar habitats. Instead they have the potential to oxidize sulfur to fuel the uptake of organic compounds for heterotrophic growth, a metabolic mode called chemolithoheterotrophy that is not found in other symbioses. Although several symbionts have heterotrophic features to supplement primary production, in Kentron they appear to supplant it entirely.


1999 ◽  
Vol 22 (4) ◽  
pp. 441-450 ◽  
Author(s):  
Bruno Cognie ◽  
Laurent Barille

2021 ◽  
Author(s):  
Muhammad Fahmi-Halil ◽  
Mohamad Haris-Hussain ◽  
Razali Mirad ◽  
AB Idris ◽  
Johari Jalinas

ABSTRACTElaeidobius kamerunicus is the main insect pollinator for oil palm (Elaeis guineensis) worldwide. One of the main reason E. kamerunicus attracted to oil palm inflorescences is estragole, a volatile organic compound released by the oil palm inflorescences during anthesis stage. However, the amount of estragole released from the oil palm inflorescence is varied due to the influence of abiotic and biotic factors and is seen to have an impact on E. kamerunicus pollination activity on the oil palm. To evaluate the responses of E. kamerunicus, different types (wild and reared) and sex (male and female) of E. kamerunicus were exposed to different concentrations (1, 5, 10, 30, 50, 70, 100, 150 and 200 ppm) of commercial estragole using four-arm olfactometer. Results showed that E. kamerunicus significantly preferred 100 ppm of estragole compared to other concentration (F = 139.81; d.f. = 9; P < 0.05). A significant interaction was also recorded between estragole concentrations and sexes of E. kamerunicus (F = 3.91; d.f. = 9; P < 0.05) where male E. kamerunicus was found to be more responsive to 100 ppm of estragole compared female E. kamerunicus. The E. kamerunicus responses to estragole is in line with the increase of estragole concentration up to 100 ppm. However, the response of E. kamerunicus was significantly decreased after the concentration value. The result of this study can be a good platform for future references since the estragole compound plays a significant role in oil palm’s flower pollination by E. kamerunicus. The factor of type and sexes of E. kamerunicus did not affect the preferences which indicated that E. kamerunicus reared in the laboratory have the potential to be released into the oil palm plantation area to overcome the problem of pollination.


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