Interrelationship between an entomogenous fungus and two ant-homopteran (Hymenoptera: Formicidae-Hemiptera: Pseudococcidae & Aphididae) mutualisms on guava trees

1983 ◽  
Vol 73 (2) ◽  
pp. 321-331 ◽  
Author(s):  
M. J. Samways
Keyword(s):  
South Africa ◽  
Food Source ◽  
Aphis Gossypii ◽  
Population Level ◽  
Normal Activity ◽  
Planococcus Citri ◽  
Entomogenous Fungus ◽  
Main Food ◽  
Main Food Source ◽  
Anoplolepis Custodiens

AbstractOn guava trees at Nelspruit, South Africa, there was a mutualism between the ant Anoplolepis custodiens (F. Sm.) and the mealybug Planococcus citri (Risso), which raised the population levels of both. When ants were excluded from half the trees, their overall population level also dropped by half. Further, they moved their nests to be as near as possible to their main food source, the honeydew of the mealybugs. When deprived of their ant mutualists, the mealybugs were heavily preyed on by coccinellids such as the ant–intolerant Exochomus flavipes (Thnb.) and the ant–tolerant Scymnus spp. Later, the mealybugs were almost totally eliminated by the primary entomogenous fungus Cladosporium sp. near C. oxysporum. The coccinellids, now without food, were forced to abandon the trees. In contrast, in trees where ants were allowed to continue their normal activity, the epizootic among the mealybugs was delayed by 14 days. This limitation by the ants of disease allowed a basal but fragmented mealybug population to survive. As the mealybugs declined, the ants switched to attending the aphid Aphis gossypii Glov. Fifteen days after the epizootic struck the ant–attended mealybug population, it began to devastate the aphid population. With both mealybugs and aphids at a low level, the ant population declined. However, the ant–homopteran mutualisms, although severely hit by the epizootic, nevertheless remained intact.

scholarly journals The benthos: the ocean’s last boundary?

2020 ◽  
Vol 84 (4) ◽  
pp. 463-475
Author(s):  
Josep-Maria Gili ◽  
Begoña Vendrell-Simón ◽  
Wolf Arntz ◽  
Francesc Sabater ◽  
Joandomènec Ros
Keyword(s):  
Water Column ◽  
Residence Time ◽  
Food Source ◽  
Benthic Communities ◽  
Strong Impact ◽  
Benthic Organisms ◽  
Main Food ◽  
Sinking Particles ◽  
Main Food Source

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.

scholarly journals Levels of Elements in Typical Mussels from the Southern Coast of Africa (Namibia, South Africa, Mozambique): Safety Aspect

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3238
Author(s):  
Pavel Nekhoroshkov ◽  
Jacques Bezuidenhout ◽  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Konstantin Vergel ◽  
...  
Keyword(s):  
South Africa ◽  
Food Source ◽  
Mytilus Galloprovincialis ◽  
Soft Tissues ◽  
Hazard Indices ◽  
The West ◽  
Calculated Risk ◽  
Permissible Levels ◽  
Main Food Source ◽  
Richards Bay

The soft tissues of mussels are often used as the main food source, especially in coastal areas. Neutron Activation Analysis was used to measure the content of 24 macro- and microelements in the soft tissues and 18 elements in the shells of selected sets of mussels of the species Mytilus galloprovincialis. The mussels were collected in 8 polluted and 4 pristine zones, which included Namibia, the west and east coasts of South Africa, and Mozambique. According to factor analysis Co, Ni, Zn, As, Se, Br, I, Sb could have anthropogenic origin. The concentrations of elements such as Cr, As, Se and partly Zn at polluted stations were above the maximum permissible levels for seafood. The concentrations of Sc, V, Cr, Mn, Co, Ni, Sb, Cs, Th, U in shells and soft tissues of the same mussels were at the close levels. Elements such as Al, Cr, Co, As (partly Zn, Se, and I) are considered to be harmful to human health at the levels of mussels consumption of 200 g/week per person and lower in such zones as Swakopmund, East London, Port Shepstone, Richards Bay, Xai-Xai according to calculated risk quotients and target hazard indices.

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
Keyword(s):  
Energy Balance ◽  
Food Source ◽  
Water Mass ◽  
Ecological Groups ◽  
Biotic Factors ◽  
Low Fat ◽  
Main Food ◽  
Different Types ◽  
Abiotic And Biotic Factors ◽  
Main Food Source

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.

A preliminary investigation of the lipids and fatty acids composition of Gammarus aequicauda (Crustacea: Amphipoda) and its main food source

2006 ◽  
Vol 86 (2) ◽  
pp. 345-348 ◽  
Author(s):  
Francesca Biandolino ◽  
Ermelinda Prato
Keyword(s):  
Fatty Acids ◽  
Food Source ◽  
Unsaturated Fatty Acids ◽  
Southern Italy ◽  
Preliminary Investigation ◽  
Monounsaturated Fatty Acids ◽  
Main Food ◽  
Gammarus Aequicauda ◽  
Chaetomorpha Linum ◽  
Main Food Source

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.

scholarly journals Diets of peracarid crustaceans associated with the orange coral Astroides calycularis in southern Spain

2015 ◽  
Vol 17 (1) ◽  
pp. 170 ◽  
Author(s):  
A. TERRÓN-SIGLERA ◽  
D. LEÓN-MUEZ ◽  
P. PEÑALVER-DUQUE ◽  
F. ESPINOSA TORRE
Keyword(s):  
Iberian Peninsula ◽  
Food Source ◽  
Southern Spain ◽  
Gut Contents ◽  
Feeding Strategies ◽  
Southern Coast ◽  
Gut Content ◽  
Main Food ◽  
Main Food Source

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.

scholarly journals Sulfur-oxidizing symbionts without canonical genes for autotrophic CO2fixation

2019 ◽  
Author(s):  
Brandon K. B. Seah ◽  
Chakkiath Paul Antony ◽  
Bruno Huettel ◽  
Jan Zarzycki ◽  
Lennart Schada von Borzyskowski ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Hydrothermal Vents ◽  
Food Source ◽  
Carbon Fixation ◽  
Carbon Sources ◽  
Coastal Sediments ◽  
Carbon Stable Isotope ◽  
Main Food ◽  
Sulfur Oxidizing ◽  
Main Food Source

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.

scholarly journals Does bivalve mucus favour the growth of their main food source, microalgae?

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