Acanthodiaptomus denticornis another omnivorous calanoid copepod: description of its mouth appendages and feeding experiments on animal prey

Hydrobiologia ◽  
1992 ◽  
Vol 248 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Nicole Lair ◽  
Maria Hilal
1988 ◽  
Vol 45 (6) ◽  
pp. 1069-1074 ◽  
Author(s):  
Charles H. Greene ◽  
Michael R. Landry

Carnivorous suspension feeding is described for the large subarctic calanoid copepod Neocalanus cristatus. This foraging mode relies on the use of a feeding current to entrain potential prey items and transport them into the copepod's capture area. The extensive use of a feeding current to entrain and transport prey into the capture area distinguishes carnivorous suspension feeding from the predatory modes typically described for other calanoid copepods. The consequences of carnivorous suspension feeding on N. cristatus' prey-selection patterns are significant. Feeding experiments reveal that the vulnerability of naupliar prey declines with increasing prey size, just the opposite result observed for other marine calanoids exhibiting more typical predatory feeding modes. The role of omnivorous feeding by N. cristatus within the pelagic ecosystem of the subarctic Pacific is also discussed. In contrast with earlier hypotheses, the results reported here are consistent with the emerging view that this large suspension-feeding copepod may be having at least as great an impact on the microzooplankton as on the phytoplankton of the region.


1993 ◽  
Vol 50 (7) ◽  
pp. 1382-1393 ◽  
Author(s):  
Hans J. Hartmann ◽  
Hassan Taleb ◽  
Lotfi Aleya ◽  
Nicole Lair

The effects of prey size, hunger, and algal presence on the predation of the suspension-feeding calanoid copepod Acanthodiaptomus denticornis on the ciliates Tetrahymena corlisii (32 μm mean length), Paramecium aurelia (114 μm), P. caudatum (124 μm), Loxodes sp. [Formula: see text], and Stentor coeruleus[Formula: see text] and the flagellate Astasia longa (14 μm) were evaluated in laboratory experiments. Adult Acanthodiaptomus consumed all species, but not in proportion to their size. At low concentrations (prey < 200 μg C∙L−1), mean clearance rates ranged from 80 mL∙copepod−1∙d−1 (for Paramecium) to 13 mL∙copepod−1∙d−1 (for Loxodes). Clearance rates declined with increasing concentration of the same prey, as expected. Prey capture and ingestion was determined by cell width and prey escape reactivity. Hunger significantly increased predation rates at high prey levels. The presence of algae enhanced ciliate predation by hungry copepods at low prey levels, but had no other significant effects. Protozoan predation by Acanthodiaptomus generally exceeds its feeding on algae and nanoplankton. Results suggest that ciliates can be a significant part of the diet of some suspension-feeding freshwater copepods in situ, confirming the importance of ciliates as mediators of energy transfer from the microbial loop to higher trophic levels.


1993 ◽  
Vol 50 (2) ◽  
pp. 410-415 ◽  
Author(s):  
Jules M. Blais ◽  
Edward J. Maly

Feeding experiments were performed to determine relative feeding rates of fourth-instar Chaoborus americanus larvae (Diptera) on both sexes of two calanoid copepod species, Diaptomus leptopus and D. minutus. Feeding rates, using a single prey type, showed that predation rates by Chaoborus on female D. minutus were highest, followed by male D. minutus, male D. leptopus, and female D. leptopus, respectively, when exposed to Chaoborus individually. Selectivity experiments with the four prey types made available simultaneously confirmed this pattern. Prey sizes and swimming speeds were determined, and both strike efficiency and handling time of Chaoborus were measured. Data suggested that selection between prey species was determined primarily by prey size whereas selection between sexes was determined primarily by differential swimming speed.


1995 ◽  
Vol 69 (1) ◽  
pp. 69-75 ◽  
Author(s):  
T. Scholz ◽  
M.C.F. Pech-Ek ◽  
R. Rodriguez-Canul

AbstractField study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopsis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22–24°C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1–35.7°C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8–35.7°C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ajeet Kumar Mohanty ◽  
Charles de Souza ◽  
Deepika Harjai ◽  
Prathamesh Ghavanalkar ◽  
Mezia Fernandes ◽  
...  

Abstract Background Efforts to study the biology of Plasmodium vivax liver stages, particularly the latent hypnozoites, have been hampered by the limited availability of P. vivax sporozoites. Anopheles stephensi is a major urban malaria vector in Goa and elsewhere in South Asia. Using P. vivax patient blood samples, a series of standard membrane-feeding experiments were performed with An. stephensi under the US NIH International Center of Excellence for Malaria Research (ICEMR) for Malaria Evolution in South Asia (MESA). The goal was to understand the dynamics of parasite development in mosquitoes as well as the production of P. vivax sporozoites. To obtain a robust supply of P. vivax sporozoites, mosquito-rearing and mosquito membrane-feeding techniques were optimized, which are described here. Methods Membrane-feeding experiments were conducted using both wild and laboratory-colonized An. stephensi mosquitoes and patient-derived P. vivax collected at the Goa Medical College and Hospital. Parasite development to midgut oocysts and salivary gland sporozoites was assessed on days 7 and 14 post-feeding, respectively. The optimal conditions for mosquito rearing and feeding were evaluated to produce high-quality mosquitoes and to yield a high sporozoite rate, respectively. Results Laboratory-colonized mosquitoes could be starved for a shorter time before successful blood feeding compared with wild-caught mosquitoes. Optimizing the mosquito-rearing methods significantly increased mosquito survival. For mosquito feeding, replacing patient plasma with naïve serum increased sporozoite production > two-fold. With these changes, the sporozoite infection rate was high (> 85%) and resulted in an average of ~ 22,000 sporozoites per mosquito. Some mosquitoes reached up to 73,000 sporozoites. Sporozoite production could not be predicted from gametocyte density but could be predicted by measuring oocyst infection and oocyst load. Conclusions Optimized conditions for the production of high-quality P. vivax sporozoite-infected An. stephensi were established at a field site in South West India. This report describes techniques for producing a ready resource of P. vivax sporozoites. The improved protocols can help in future research on the biology of P. vivax liver stages, including hypnozoites, in India, as well as the development of anti-relapse interventions for vivax malaria.


1935 ◽  
Vol 112 (1) ◽  
pp. 283-302 ◽  
Author(s):  
Richard H. McCoy ◽  
Curtis E. Meyer ◽  
William C. Rose

Sign in / Sign up

Export Citation Format

Share Document