scholarly journals Occurrence and influence of bopyrid parasites on female penaeid prawns from coastal waters of central Queensland (Australia)

1991 ◽  
Vol 42 (6) ◽  
pp. 615 ◽  
Author(s):  
AJ Courtney

The prevalence of bopyrid isopods, parasitic on penaeid prawn hosts, is recorded for the first time from a central Queensland prawn trawl fishery. The bopyrid parasite Parapenaeon prox. expansus has been recorded for the first time from the red spot king prawn, Penaeus longistylus, and the blue-legged king prawn, Penaeus latisulcatus. Previous unpublished reports of Parapenaeon japonicum parasitizing P. longistylus have also been substantiated. Parasite species were not randomly associated with all prawn species but rather were associated with a single prawn host species or species group. The factors that give rise to such specific host-parasite associations, particularly the host-selective behaviour of the parasite and the habitat preferences of the juvenile prawns, are discussed. Bopyrids had no significant effect on the weight of the prawns, but they did have a significant effect on ovary weight and histology, causing sterility in their hosts. High levels of infestation have been recorded from other fisheries (resulting in reduced spawning potential of the host population), but the low prevalence (0.32%) of bopyrid parasites in central Queensland prawns appears to be so low as not to present a concern at present.

1958 ◽  
Vol 90 (3) ◽  
pp. 179-191 ◽  
Author(s):  
T. Burnett

That insect parasites regulate and, in the case of newly introduced species, sometimes reduce the average density of insect pests has led to an exmination of the properties of parasites in general. Consideration has been given to the manner in which parasites select hosts for oviposition and to the physiological and psychological basis of this selection. The distribution of parasite progeny among suitable hosts has been analysed in many cases, for the fewer the hostS that are superparasitized for any given number of parasite eggs laid the greater the efficiency of the parasite in reducing host density. It is obvious that before the factors of host selection and superparasitism become important in host-parasite interaction the parasite must find the host individuals. When the hosts are confined to a relatively small area the potential oviposition of the parasite, subject to discrimination among hosts and restraint in oviposition, often determines the level of parasitism. As distance between individuals of the host population becomes greater, however, it is necessary for the parasite to search the environment more extensively. Therefore, the ability of the parasite to find hosts is a factor of prime importance in determining its influence on the density of its host. The success with which a parasite discovers hosts in relation to host density is determined, of course, by several characteristics of the parasite species and by the modification of these characteristics through variations in the physical environment.


Zootaxa ◽  
2019 ◽  
Vol 4582 (1) ◽  
pp. 1
Author(s):  
ZINGISILE MBO ◽  
CHARLES R. HADDAD

The genus Drassodella Hewitt, 1916 is one of four Afrotropical genera of Gallieniellidae, and is presently represented by seven species, all endemic to South Africa. The type material of six of the described species was studied and they are redescribed from both sexes: D. melana Tucker, 1923, D. quinquelabecula Tucker, 1923, D. salisburyi Hewitt, 1916, D. septemmaculata (Strand, 1909), D. tenebrosa Lawrence, 1938 and D. vasivulva Tucker, 1923. Of these, the males of D. melana, D. tenebrosa and D. vasivulva are described for the first time. Recent field work yielded additional females of D. purcelli Tucker, 1923 from the vicinity of the type locality, and this sex is redescribed; the male remains unknown. A further 12 new species are recognized: D. amatola sp. nov. (♀ ♂), D. aurostriata sp. nov. (♀ ♂), D. baviaans sp. nov. (♂), D. flava sp. nov. (♀ ♂), D. guttata sp. nov. (♀ ♂), D. lotzi sp. nov. (♀), D. maculata sp. nov. (♀), D. montana sp. nov. (♀ ♂), D. tolkieni sp. nov. (♀ ♂), D. trilineata sp. nov. (♀), D. transversa sp. nov. (♀ ♂) and D. venda sp. nov. (♀ ♂). Based on the genitalic structures, there appear to be two distinct species groups. The D. melana species group, which includes D. melana, D. tenebrosa and eight new species mainly distributed in eastern and northern South Africa, is characterised by very conservative genitalic morphology in both sexes. The D. salisburyi species group, with considerable variation in the structure of the copulatory organs and distributed in the southern half of South Africa, includes the remaining nine species, of which four are new. Although D. tenebrosa represents an intermediate between the two groups, with palpal morphology more typical of the D. melana species group and epigynal morphology typical of the D. salisburyi group, it is placed in the former species group based on its distribution in eastern South Africa. The biology, habitat preferences and biogeography of Drassodella are briefly discussed. 


Parasitology ◽  
2017 ◽  
Vol 145 (6) ◽  
pp. 770-774 ◽  
Author(s):  
Benjamin J. Z. Quigley ◽  
Sam P. Brown ◽  
Helen C. Leggett ◽  
Pauline D. Scanlan ◽  
Angus Buckling

AbstractCompetition between parasite species or genotypes can play an important role in the establishment of parasites in new host populations. Here, we investigate a mechanism by which a rare parasite is unable to establish itself in a host population if a common resident parasite is already present (a ‘priority effect’). We develop a simple epidemiological model and show that a rare parasite genotype is unable to invade if coinfecting parasite genotypes inhibit each other's transmission more than expected from simple resource partitioning. This is because a rare parasite is more likely to be in multiply-infected hosts than the common genotype, and hence more likely to pay the cost of reduced transmission. Experiments competing interfering clones of bacteriophage infecting a bacterium support the model prediction that the clones are unable to invade each other from rare. We briefly discuss the implications of these results for host-parasite ecology and (co)evolution.


2017 ◽  
Vol 284 (1866) ◽  
pp. 20171615 ◽  
Author(s):  
Alex Best ◽  
Ben Ashby ◽  
Andy White ◽  
Roger Bowers ◽  
Angus Buckling ◽  
...  

Fluctuating selection driven by coevolution between hosts and parasites is important for the generation of host and parasite diversity across space and time. Theory has focused primarily on infection genetics, with highly specific ‘matching-allele’ frameworks more likely to generate fluctuating selection dynamics (FSD) than ‘gene-for-gene’ (generalist–specialist) frameworks. However, the environment, ecological feedbacks and life-history characteristics may all play a role in determining when FSD occurs. Here, we develop eco-evolutionary models with explicit ecological dynamics to explore the ecological, epidemiological and host life-history drivers of FSD. Our key result is to demonstrate for the first time, to our knowledge, that specificity between hosts and parasites is not required to generate FSD. Furthermore, highly specific host–parasite interactions produce unstable, less robust stochastic fluctuations in contrast to interactions that lack specificity altogether or those that vary from generalist to specialist, which produce predictable limit cycles. Given the ubiquity of ecological feedbacks and the variation in the nature of specificity in host–parasite interactions, our work emphasizes the underestimated potential for host–parasite coevolution to generate fluctuating selection.


Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 725
Author(s):  
David Becerro-Recio ◽  
Javier González-Miguel ◽  
Alberto Ucero ◽  
Javier Sotillo ◽  
Álvaro Martínez-Moreno ◽  
...  

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.


Zootaxa ◽  
2020 ◽  
Vol 4820 (1) ◽  
pp. 177-185
Author(s):  
TIANQI LAN ◽  
ZHIYUAN YAO ◽  
ABID ALI ◽  
GUO ZHENG ◽  
SHUQIANG LI

The genus Pholcus Walckenaer, 1805 is reported from Pakistan for the first time. Two new species of the Pholcus nenjukovi species-group are described: Pholcus hamuchal Yao & Li sp. nov. (Gilgit Baltistan, male and female) and Pholcus kalam Yao & Li sp. nov. (Khyber Pakhtunkhwa, male and female). Type material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.


Zootaxa ◽  
2018 ◽  
Vol 4399 (2) ◽  
pp. 295
Author(s):  
ALEXEY V. SHAVRIN

Two new species of the genus Olophrum Erichson, 1839 of the laxum group are described and illustrated: O. lama Shavrin, sp.n. (Nepal: Rolwaling Himal) and O. schuelkei Shavrin, sp.n. (China: Shaanxi). Olophrum laxum Shavrin & Smetana, 2017 from Yunnan and O. pacei Shavrin & Smetana, 2017 from Shaanxi and Hubei provinces of China are recorded for the first time. A modified key of the laxum group is provided. 


1976 ◽  
Vol 7 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Ebbe Schmidt Nielsen ◽  
Ole Karsholt

AbstractNotes are given on the identity and synonymy of five species of Lepidoptera described by Linnaeus, twenty-eight by Fabricius and two by Ström. Each species dealt with is treated under the apparent valid combination; for each species reference is given to the original description. Twenty-four new species-group name synonyms are introduced and nine new combinations are established: Nemaxera betulinella (Fabr.), Argyresthia arcella (Fabr.), Depressaria depressana (Fabr.), Chrysoesthia drurella (Fabr.), Brachmia blandella (Fabr.), Acleris laterana (Fabr.), Pseudohermenias abietana (Fabr.), Epinotia abbreviana (Fab.) and Acrobasis repandana (Fabr.). During the work two neotypes, twenty-seven lectotypes and two paralectotypes have been designated and are here cited for the first time.


Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1176-1182 ◽  
Author(s):  
C. A. RAUQUE ◽  
R. A. PATERSON ◽  
R. POULIN ◽  
D. M. TOMPKINS

SUMMARYThere is a gap in our understanding of the relative and interactive effects of different parasite species on the same host population. Here we examine the effects of the acanthocephalan Acanthocephalus galaxii, an unidentified cyclophyllidean cestode, and the trematodes Coitocaecum parvum and Microphallus sp. on several fitness components of the amphipod Paracalliope fluviatilis, using a combination of infection surveys and both survival and behavioural trials. In addition to significant relationships between specific parasites and measures of amphipod survival, maturity, mating success and behaviour, interactions between parasite species with respect to amphipod photophilia were also significant. While infection by either A. galaxii or C. parvum was associated with increased photophilia, such increases were negated by co-infection with Microphallus sp. We hypothesize that this is due to the more subtle manipulative effect of A. galaxii and C. parvum being impaired by Microphallus sp. We conclude that the low frequency at which such double infections occur in our sampled population means that such interactions are unlikely to be important beyond the scale of the host individual. Whether or not this is generally true, implying that parasitological models and theory based on single parasite species studies do generally hold, requires cross-species meta-analytical studies.


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