Occurrence of nematode parasites in Calocaris macandreae (Crustacea: Decapoda) from an Irish Sea population

1986 ◽  
Vol 66 (2) ◽  
pp. 293-301 ◽  
Author(s):  
J. A. Perez-Calderon
Keyword(s):  
Life Cycle ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Decapod Crustacean ◽  
Host Cells ◽  
Complex Life Cycle ◽  
Irish Sea ◽  
Shore Crab ◽  
Melanogrammus Aeglefinus ◽  
Decapod Crustaceans

INTRODUCTIONA number of nematodes are known to develop in decapod crustaceans. These parasite nematodes are present in the coelom of the host either free or surrounded by different types of host cells. All belong to the order Ascaridida or Spirurida and most of them develop only to the third larval stage in the decapod host; further development takes place in a predator of the crustacean which is generally a teleost or elasmobranch (Berland, 1961; Ouspenskaia, 1960; Petter, 1970; Poinar & Kuris, 1975;Uspenskaja, 1953; Yamaguti, 1961). The life-cycle in most cases is not fully understood. Ouspenskaia (1960) and Uspenskaja (1953, 1963) deduced the life-cycle for Ascarophis morrhuae van Beneden and A. filiformis Poljanski in the Barents Sea by relating the larvae found in decapod crustaceans through affinity of characters to the adults present in cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.). Similarly, the life-cycle of the spirurid Proleptus obtusus was described by Lloyd (1928); the larvae occur in a decapod crustacean, usually the hermit crab Pagurus bernhardus L. and in some cases the shore crab Carcinus maenas L. and the adults are found in the lesser spotted dogfish (Scyliorhinus canicula L.). A more complex life-cycle has been proposed for some anisakids such as Anisakis, Contracaecum and Hysterothylacium (Berland, 1961; Norris & Overstreet, 1976; Wootten, 1978) in which more than one intermediate host is required.

scholarly journals Glutamine Analogues Impair Cell Proliferation, the Intracellular Cycle and Metacyclogenesis in Trypanosoma cruzi

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1628
Author(s):  
Rodolpho Ornitz Oliveira Souza ◽  
Marcell Crispim ◽  
Ariel Mariano Silber ◽  
Flávia Silva Damasceno
Keyword(s):  
Cell Proliferation ◽  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Host Cells ◽  
Glutamine Metabolism ◽  
Complex Life Cycle ◽  
Mammalian Host ◽  
Developmental Cycle ◽  
Parasite Life Cycle

Trypanosoma cruzi is the aetiologic agent of Chagas disease, which affects people in the Americas and worldwide. The parasite has a complex life cycle that alternates among mammalian hosts and insect vectors. During its life cycle, T. cruzi passes through different environments and faces nutrient shortages. It has been established that amino acids, such as proline, histidine, alanine, and glutamate, are crucial to T. cruzi survival. Recently, we described that T. cruzi can biosynthesize glutamine from glutamate and/or obtain it from the extracellular environment, and the role of glutamine in energetic metabolism and metacyclogenesis was demonstrated. In this study, we analysed the effect of glutamine analogues on the parasite life cycle. Here, we show that glutamine analogues impair cell proliferation, the developmental cycle during the infection of mammalian host cells and metacyclogenesis. Taken together, these results show that glutamine is an important metabolite for T. cruzi survival and suggest that glutamine analogues can be used as scaffolds for the development of new trypanocidal drugs. These data also reinforce the supposition that glutamine metabolism is an unexplored possible therapeutic target.

Understanding limits to cod and haddock separation using size selectivity in a multispecies trawl fishery: an application of FISHSELECT

2011 ◽  
Vol 68 (5) ◽  
pp. 927 ◽  
Author(s):  
Manu Sistiaga ◽  
Bent Herrmann ◽  
Kåre N. Nielsen ◽  
Roger B. Larsen
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Morphological Characteristics ◽  
Melanogrammus Aeglefinus ◽  
Size Selectivity ◽  
Sea Trial ◽  
Trawl Fishery ◽  
The Barents Sea ◽  
Morphological Differences

This investigation demonstrates how a multidisciplinary approach based on the FISHSELECT framework, sea trial data, underwater recordings, and laboratory investigations of netting can be applied to size selectivity studies and related management issues. We studied the morphological characteristics of Atlantic cod ( Gadus morhua ) and haddock ( Melanogrammus aeglefinus ) in the Barents Sea bottom trawl fishery. The differences between the L50 values (i.e., the size at which a fish has a 50% chance of being retained) that were recorded for the two species during sea trials can to a large extent be explained by the morphological differences between them. Because of these morphological differences, L50 is always larger for cod than for haddock with the grid and codend setup commonly used in the area. While catch separation of cod and haddock is a management objective in the Barents Sea, we demonstrate that the morphological differences between the species and the grid and codend setup in force today limit achievable differences in L50 to 5.5 cm. Furthermore, we show that for this fishery, the scope for increasing L50 differences between these species by changing the mesh shape configuration of the codend is minimal.

Diet overlap and prey selection through metamorphosis in Irish Sea cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and whiting (Merlangius merlangus)

2008 ◽  
Vol 65 (7) ◽  
pp. 1297-1306 ◽  
Author(s):  
William Ll. Rowlands ◽  
Mark Dickey-Collas ◽  
Audrey J. Geffen ◽  
Richard D.M. Nash
Keyword(s):  
Gadus Morhua ◽  
Prey Selection ◽  
Stomach Contents ◽  
Irish Sea ◽  
Melanogrammus Aeglefinus ◽  
Prey Preferences ◽  
Merlangius Merlangus ◽  
The Irish Sea ◽  
Haddock Melanogrammus Aeglefinus ◽  
Calanus Species

Copepods in the genus Calanus are usually considered to be the preferred prey of gadoid larvae in many areas; however, in the Irish Sea, the abundances of these Calanus species are low and highly variable. We use this situation to test whether Calanus species are still actively selected by gadoid larvae in Calanus -poor environments. Diets of Irish Sea cod ( Gadus morhua ), haddock ( Melanogrammus aeglefinus ), and whiting ( Merlangius merlangus ) were studied from the yolk-sac stage to the juvenile stage. Prey from stomach contents were compared with in situ abundance via an index of prey preference. As expected, all larvae selected copepod nauplii at the onset of feeding. As the larvae developed, their prey preferences changed and varied with species. Cod and whiting showed a similar transition of prey species preference, with a clear preference for Calanus species after metamorphosis, even in this area of low abundance of these Calanus species. The diet composition of haddock differed from that of cod and whiting, as nauplii remained in their diet later into development and there was little preference for individual copepod species detected. The differences in prey selectivity suggested between these gadoids may be attributed to their population variability through the known variability of their preferred prey items.

scholarly journals Fishery discards in the Irish Sea exhibit temporal oscillations and trends reflecting underlying processes at an annual scale

2010 ◽  
Vol 68 (1) ◽  
pp. 221-227 ◽  
Author(s):  
Mafalda Viana ◽  
Norman Graham ◽  
James G. Wilson ◽  
Andrew L. Jackson
Keyword(s):  
Gadus Morhua ◽  
Temporal Dynamics ◽  
Stock Assessment ◽  
Irish Sea ◽  
Melanogrammus Aeglefinus ◽  
Annual Cycles ◽  
The Irish Sea ◽  
Fishery Discards ◽  
Annual Scale ◽  
Underlying Processes

Abstract Viana, M., Graham, N., Wilson, J. G., and Jackson, A. L. 2011. Fishery discards in the Irish Sea exhibit temporal oscillations and trends reflecting underlying processes at an annual scale. – ICES Journal of Marine Science, 68: 221–227. Non-inclusion of discard data in stock assessment can lead to underestimation of biomass and fishing mortality; this is of particular concern if there have been changes in discard practices over time. Although variability in space and time is a well-documented feature of discards, the temporal dynamics of the practice has received little detailed attention. The aim here is to characterize the temporal patterns of discarding practices in the Irish Sea (ICES Division VIIa) from 1994 to 2008. Trend and seasonality were explored in discards per unit effort (dpue) of haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and cod (Gadus morhua) through Bayesian harmonic regression (HREG) models. The HREG models reveal discarding of all three species in annual cycles, with a peak in the second quarter, perhaps reflecting species biology or fisher behaviour, or both. The dpue of cod cycled around a constant level throughout the observation period, but whiting and haddock dpue increased.

scholarly journals Thermal dynamics of ovarian maturation in Atlantic cod (Gadus morhua)

2010 ◽  
Vol 67 (4) ◽  
pp. 605-625 ◽  
Author(s):  
Olav Sigurd Kjesbu ◽  
David Righton ◽  
Maria Krüger-Johnsen ◽  
Anders Thorsen ◽  
Kathrine Michalsen ◽  
...  
Keyword(s):  
Water Temperature ◽  
Data Storage ◽  
Egg Production ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Field Studies ◽  
Irish Sea ◽  
Oocyte Growth ◽  
Thermal Dynamics

The timing and success of spawning in marine fish are of fundamental importance to population persistence and distribution and, for commercial species, sustainability. Their physiological processes of reproduction are regulated, in part, by water temperature, and therefore changes in marine climate may have dramatic effects on spawning performance. Using adult Atlantic cod ( Gadus morhua ) as a case study, we examined the links between water temperature, body size, vitellogenesis, and spawning time by conducting extensive laboratory and field studies. Our experiments documented that vitellogenesis generally starts at autumnal equinox and that oocyte growth and investment are greater in cod held at warmer temperatures. Furthermore, spawning occurred earlier when oocyte growth was more rapid. Large females spawned earlier than smaller females at warmer temperatures, but this effect vanished at colder temperatures. The experimental results were confirmed by measurements of oocyte growth collected from wild-caught cod in northern (Barents Sea) and southern (Irish Sea and North Sea) populations. The established, general model of oocyte maturation was consistent with published egg production curves of cod from these waters, considering relevant in situ temperatures recorded by individual data-storage tags on cod. These findings have considerable relevance for future studies of fish recruitment in relation to climate change.

scholarly journals The sampling volume of trawl and acoustics: estimating availability probabilities from observations of tracked individual fish

2009 ◽  
Vol 66 (3) ◽  
pp. 425-437 ◽  
Author(s):  
Nils Olav Handegard ◽  
Dag Tjøstheim
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Initial Position ◽  
Bottom Trawl ◽  
Melanogrammus Aeglefinus ◽  
Individual Fish ◽  
Sampling Volume ◽  
Swimming Trajectories ◽  
Echo Sounder

The effective sampling volume of trawl and acoustics is an important parameter in fish abundance estimation surveys. This paper presents a method to compute the probability of a fish being available to the bottom trawl and the probability of it being seen on the echo sounder, given its initial position relative to the vessel path. These probabilities are then related to the calculation of the effective observational volume for trawl and acoustics, the two main tools of measuring abundance of Atlantic cod ( Gadus morhua ) and haddock ( Melanogrammus aeglefinus ). As an example, the computation is carried out for a typical vertical distribution in the Barents Sea. Our model is based on an Ornstein–Uhlenbeck model for the fish swimming trajectories, and its parameters are estimated using observations of swimming trajectories for individual fish, recorded by a split-beam echo sounder. The model itself constitutes a general method to translate observations on behaviour of individual fish to probability maps. The results indicate a typical fishing height of 20 m for the bottom trawl, but it is also shown that there is a relatively low probability of catching by the trawl what you see on the echo sounder, even for fish positioned directly in the trawl path. This is because of strong lateral movements of the fish.

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