Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

1998 ◽  
Vol 38 (7) ◽  
pp. 73-79 ◽  
Author(s):  
Hooi-Ling Lee ◽  
Donald DeAngelis ◽  
Hock-Lye Koh
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Success Rate ◽  
Distribution Patterns ◽  
Fish Host ◽  
Limited Movement ◽  
Unionid Mussels ◽  
Species Characteristics ◽  
Major Factors ◽  
Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

Encystment site affects the reproductive strategy of a progenetic trematode in its fish intermediate host: is host spawning an exit for parasite eggs?

Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1183-1192 ◽  
Author(s):  
KRISTIN K. HERRMANN ◽  
ROBERT POULIN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Body Cavity ◽  
Life Cycles ◽  
Temperature Changes ◽  
Fish Spawning ◽  
Second Intermediate Host ◽  
Host Life ◽  
Major Factors ◽  
Fish Hosts

SUMMARYEach transmission event in complex, multi-host life cycles create obstacles selecting for adaptations by trematodes. One such adaptation is life cycle abbreviation through progenesis, in which the trematode precociously matures and reproduces within the second intermediate host. Progenesis eliminates the need for the definitive host and increases the chance of life cycle completion. However, progenetic individuals face egg-dispersal challenges associated with reproducing within metacercarial cysts in the tissues or body cavity of the second intermediate host. Most progenetic species await host death for their eggs to be released into the environment. The present study investigated temporal variation of progenesis in Stegodexamene anguillae in one of its second intermediate fish hosts and the effect of the fish's reproductive cycle on progenesis. The study involved monthly sampling over 13 months at one locality. A greater proportion of individuals became progenetic in the gonads of female fish hosts. Additionally, progenesis of worms in the gonads was correlated with seasonal daylight and temperature changes, major factors controlling fish reproduction. Host spawning events are likely to be an avenue of egg dispersal for this progenetic species, with the adoption of progenesis being conditional on whether or not the parasite can benefit from fish spawning.

scholarly journals The occurrence and dynamics of Ligula intestinalis in its cyprinid fish host, tench, Tinca tinca, in MoganLake (Ankara, Turkey)

2012 ◽  
Vol 50 (No. 12) ◽  
pp. 537-542
Author(s):  
Ergonul MB ◽  
A. Altindag
Keyword(s):  
Life Cycle ◽  
Fish Host ◽  
Cyprinid Fish ◽  
Fish Sample ◽  
Tinca Tinca ◽  
Mean Intensity ◽  
Ligula Intestinalis ◽  
The Mean ◽  
Tench Tinca Tinca ◽  
Fish Hosts

Although Ligula intestinalis (L., 1758) has been recorded in several fish hosts, available data on the parasitization parameters of Ligula intestinalis plerocercoids such as prevalence, mean intensity and parasitic index in tench (Tinca tinca L., 1758) is limited. In this study, totally 272 fishes were investigated for the presence of L. intestinalis plerocercoids. The prevalence value was 40.01% of the whole fish sample and the mean intensity was 2.48. The lower IP values and mean intensity levels may provide some evidence of the strategy of Ligula in order to complete its life cycle. None of the parasitization parameters showed significant differences between the sexes.

Biology of Bothrimonus (= Diplocotyle) (Pseudophyllidea: Cestoda): Ecology, Life Cycle, and Evolution; a Review and Synthesis

1972 ◽  
Vol 29 (10) ◽  
pp. 1381-1395 ◽  
Author(s):  
I. M. Sandeman ◽  
M. D. B. Burt
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Intermediate Host ◽  
Brackish Water ◽  
Sexual Maturity ◽  
Fish Host ◽  
Short Life ◽  
Larval Stages ◽  
Short Life Span ◽  
Fish Hosts

An integrated account of the ecology and life cycle of Bothrimonus is synthesized from the literature, experiment, and observation of larval and adult stages of the parasite. Bothrimonus has a circumpolar distribution in boreal or subarctic conditions. As an adult it is found in a wide variety of fish hosts which feed in littoral or estuarine waters. Adult worms have a short life-span in the fish host and occur only seasonally. A single intermediate host appears to be involved in the life cycle and this is most commonly a brackish-water gammarid. The operculate eggs, which contain unciliated larvae, possess characteristic polar filaments which have an adhesive function. Entry is almost certainly by ingestion of eggs by the gammarid host; the larval forms often attain sexual maturity within the gammarid host with accompanying production of apparently normal eggs. Although it has been possible to infect fish hosts experimentally with larval stages, it has not yet been possible to infect gammarids with eggs obtained either from neotenic individuals in gammarids or from adults in the fish host.The life cycle of Bothrimonus indicates closer affinities of the Cyathocephalidae with caryophyllaeid than with other pseudophyllidean tapeworms. Distribution is discussed in terms of its evolution and a freshwater origin in the Ponto–Aralo–Caspian province is proposed.

scholarly journals Spatio-temporal distribution patterns of Plutella xylostella (Lepidoptera: Plutellidae) in a fine-scale agricultural landscape based on geostatistical analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Yu Li ◽  
Yan-Ting Chen ◽  
Meng-Zhu Shi ◽  
Jian-Wei Li ◽  
Rui-Bin Xu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Plutella Xylostella ◽  
Agricultural Landscape ◽  
Seasonal Pattern ◽  
Distribution Patterns ◽  
Geostatistical Analysis ◽  
Distribution Model ◽  
Detailed Knowledge ◽  
Fine Scale ◽  
Spatio Temporal

AbstractA detailed knowledge on the spatial distribution of pests is crucial for predicting population outbreaks or developing control strategies and sustainable management plans. The diamondback moth, Plutella xylostella, is one of the most destructive pests of cruciferous crops worldwide. Despite the abundant research on the species’s ecology, little is known about the spatio-temporal pattern of P. xylostella in an agricultural landscape. Therefore, in this study, the spatial distribution of P. xylostella was characterized to assess the effect of landscape elements in a fine-scale agricultural landscape by geostatistical analysis. The P. xylostella adults captured by pheromone-baited traps showed a seasonal pattern of population fluctuation from October 2015 to September 2017, with a marked peak in spring, suggesting that mild temperatures, 15–25 °C, are favorable for P. xylostella. Geostatistics (GS) correlograms fitted with spherical and Gaussian models showed an aggregated distribution in 21 of the 47 cases interpolation contour maps. This result highlighted that spatial distribution of P. xylostella was not limited to the Brassica vegetable field, but presence was the highest there. Nevertheless, population aggregations also showed a seasonal variation associated with the growing stage of host plants. GS model analysis showed higher abundances in cruciferous fields than in any other patches of the landscape, indicating a strong host plant dependency. We demonstrate that Brassica vegetables distribution and growth stage, have dominant impacts on the spatial distribution of P. xylostella in a fine-scale landscape. This work clarified the spatio-temporal dynamic and distribution patterns of P. xylostella in an agricultural landscape, and the distribution model developed by geostatistical analysis can provide a scientific basis for precise targeting and localized control of P. xylostella.

Host specificity of Argulus coregoni (Crustacea: Branchiura) increases at maturation

Parasitology ◽  
2007 ◽  
Vol 134 (12) ◽  
pp. 1767-1774 ◽  
Author(s):  
V. N. MIKHEEV ◽  
A. F. PASTERNAK ◽  
E. T. VALTONEN
Keyword(s):  
Host Specificity ◽  
Host Preference ◽  
Oxygen Depletion ◽  
Host Choice ◽  
Fish Host ◽  
Argulus Foliaceus ◽  
Argulus Coregoni ◽  
Suitable Habitats ◽  
Fish Hosts ◽  
Higher Sensitivity

SUMMARYWe tested the hypothesis that host specificity in ectoparasites does not depend exclusively on the features of the host but also on surrounding habitats, using 2 fish ectoparasites, Argulus coregoni and A. foliaceus (Crustacea: Branchiura), occurring sympatrically in Finnish lakes. Although these parasites are considered to be of low specificity, we found that the larger of the 2 species, A. coregoni developed a pronounced preference for salmonid hosts at the beginning of maturation (defined by the presence of copulating specimens). Argulus foliaceus infects a much wider range of fish hosts. We showed that specialization of A. coregoni on salmonids does not necessarily result from incompatibility with other fishes, but could instead reflect higher sensitivity of oxygen depletion compared with A. foliaceus. Adult A. coregoni may meet these demands by attaching to salmonids, the typical inhabitants of well-aerated waters. Young parasites of both species showed little host specificity and attached mainly to fishes with higher body reflectivity. In host choice experiments, A. coregoni of 4–5 mm length preferred salmonids (rainbow trout) to cyprinids (roach) irrespective of the type of fish host, on which it had been previously grown in the laboratory. We suggest that such an innate ontogenetic shift in host preference maintains the major part of the parasite population on its principal host, ensuring successful reproduction within suitable habitats.

Sign in / Sign up

Export Citation Format

Share Document