Interactions of fish and pelagic coelenterates

1988 ◽  
Vol 66 (9) ◽  
pp. 1913-1927 ◽  
Author(s):  
Mary Needler Arai
Keyword(s):  
Chum Salmon ◽  
Larval Fish ◽  
Trophic Position ◽  
Stomach Contents ◽  
Caloric Content ◽  
Feeding Rates ◽  
Intermediate Hosts ◽  
Important Species ◽  
Atlantic Mackerel ◽  
Commercially Important

Coelenterates may be predators or prey of fish, act as intermediate hosts for parasites, or provide shelter. At least 42 species of fish, including such commercially important species as the spiny dogfish, chum salmon, Atlantic mackerel, and various gadoids, include pelagic coelenterates in their diets. Coelenterates may represent a substantial proportion of the fish stomach contents and preliminary data on caloric content of coelenterates is available. However, in the absence of measured digestion rates it is not possible to calculate feeding rates or assess the dietary importance of coelenterates to fish. Similarly, although many instances of coelenterates eating larval fish are known, only a few measurements of predation rates based on feeding rates and abundances of predator and prey have yet been made. Recent studies with newer sampling methods indicate that the biomass of coelenterates, particularly large scyphomedusae, has been underestimated. Hence, much quantitative work needs to be done on the interactions of coelenterates with both fish and other marine groups to evaluate their trophic position and importance in pelagic ecosystems.

scholarly journals Feeding of the Brycon cephalus, Triportheus elongatus and Semaprochilodus insignis (osteichthyes, characiformes) larvae in Solimões/Amazonas River and floodplain areas.

2002 ◽  
Vol 32 (3) ◽  
pp. 499-499 ◽  
Author(s):  
Rosseval Galdino LEITE ◽  
Carlos A.R.M. ARAUJO-LIMA
Keyword(s):  
Food Item ◽  
Prey Size ◽  
Larval Fish ◽  
Fish Larvae ◽  
Trophic Relations ◽  
Fish Feeding ◽  
Important Species ◽  
Flooded Forests ◽  
Commercially Important

Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.

Zeros as a result in diet studies, is this really bad? Rhinoptera steindachneri as a case study

2019 ◽  
Vol 99 (7) ◽  
pp. 1661-1666 ◽  
Author(s):  
N. R. Ehemann ◽  
L. A. Abitia-Cardenas ◽  
A. F. Navia ◽  
P. A. Mejía-Falla ◽  
V. H. Cruz-Escalona
Keyword(s):  
Eating Habits ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Geographic Location ◽  
La Paz ◽  
Important Species ◽  
Mexican Pacific ◽  
Important Prey ◽  
Commercially Important ◽  
Prey Handling

AbstractRhinoptera steindachneri is a commercially important, medium-sized, pelagic migratory batoid fish with benthic feeding habits. It has been considered a specialized predator that feeds on molluscs as well as benthic ophiurids and arthropods off the Mexican Pacific coast. Most biological aspects of this species in La Paz Bay are unknown, despite its being a commercially important species of conservation interest. Therefore, the aim of this study was to characterize the feeding habits of R. steindachneri based on specimens caught in artisanal fisheries. The stomach contents of 310 specimens (146 females and 164 males) were analysed, all captured from 2013 to 2015. The vacuity index was 97.1%, and the most important prey species were Mysidium spp. and Cylichna spp. Because of the high frequency of empty stomachs recorded, it was not possible to describe with precision the general diet of the species. Three hypotheses were developed to try to explain why this characteristic occurred in this species, ranging from eating habits to physiology and prey digestion and geographic location of the study. However, considering the mechanical process of prey handling of R. steindachneri, several hypotheses were formulated, with the hour of capture, chemical processes and physiology and prey digestion being the most probable to explain this high vacuity index reported in this study.

Comparison between Gompertz and von Bertalanffy Curves for Expressing Growth in Weight of Fishes

1969 ◽  
Vol 26 (1) ◽  
pp. 161-165 ◽  
Author(s):  
R. P. Silliman
Keyword(s):  
Chum Salmon ◽  
Lake Trout ◽  
Asymptotic Limit ◽  
Von Bertalanffy ◽  
Important Species ◽  
Commercially Important

The two types of curves were fitted to empirical weights-at-age for four commercially important species: sardines, haddock, lake trout, and chum salmon. For the range of observed data, both curves fit the empirical points well, and seem almost indistinguishable on this basis. The upper asymptotic limit of weight, however, was higher for the von Bertalanffy than for the Gompertz, in all four examples. Fitting complexity is similar for both types of curves, but the Gompertz does not require the assumption of cubic length–weight relation implicit in the Beverton–Holt treatment of the von Bertalanffy.

scholarly journals Missing link: California rock crabs serve as intermediate hosts for the parasite Helicometrina nimia

2020 ◽  
Vol 94 ◽  
Author(s):  
K.M. Shanebeck ◽  
B. Presswell ◽  
C. Lagrue
Keyword(s):  
Native Species ◽  
Marine Invertebrates ◽  
Ecological Modelling ◽  
Intermediate Hosts ◽  
Important Species ◽  
Missing Link ◽  
Parasite Communities ◽  
Rock Crab ◽  
Commercially Important ◽  
Host Behaviour

Abstract Parasites can have strong effects on invertebrate host behaviour, fecundity and survival in marine ecosystems. However, parasites are often poorly documented and still rarely integrated into marine ecological modelling; comprehensive surveys of infection in marine invertebrates are sporadic at best. For example, rock crabs are an important part of Californian coastal ecosystems, both as regulators of mussel populations and non-native species, and as prey items for predators like sea otters, but their parasite communities and potential effects on crab population dynamics are seldom studied or understood. Here, we present the first report of infection by the trematode Helicometrina nimia in the economically and ecologically important red rock crab (Cancer productus) and Pacific rock crab (Romaleon antennarium). As intermediate hosts, they are a missing link for infection by H. nimia in Californian fish that was unreported until now. Based on these findings, we advocate for further research into parasite diversity and their potential effects on ecologically and commercially important species.

scholarly journals Fish larvae off the northwestern coast of the Baja California Peninsula, Mexico

Check List ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 334 ◽  
Author(s):  
S. Patricia A. Jiménez-Rosenberg ◽  
Ricardo J. Saldierna-Martínez ◽  
Gerardo Aceves-Medina ◽  
Alejandro Hinojosa-Medina ◽  
René Funes-Rodríguez ◽  
...  
Keyword(s):  
Reproductive Behavior ◽  
Fish Assemblage ◽  
Community Dynamics ◽  
Baja California ◽  
Larval Fish ◽  
Fish Larvae ◽  
Distribution Patterns ◽  
Baja California Peninsula ◽  
Important Species ◽  
Commercially Important

The structure of the larval fish assemblage of the northwestern Pacific coast of Mexico is analyzed from zooplankton samples taken between 1998 and 2000 off northern and southern Baja California Peninsula. The 198 fish taxa identified reflected the faunal complexity reported previously for the area. Adult distribution patterns and reproductive behavior, added to the environmental seasonality and bathymetric characteristics of the coast, explained differences in the larval fish assemblage. Larvae of meso- and bathypelagics Vinciguerria lucetia, Diogenichthys laternatus, and Triphoturus mexicanus were the most abundant year round. Larvae of commercially important species, such as Engraulis mordax, Sardinops sagax, Merluccius productus, and Trachurus symmetricus, were also abundant during winter and spring, depending on the year and surveyed region. Adult distribution patterns and reproductive behavior, intra- and interannual environmental variability, and bathymetric characteristics of the coast all likely contributed to the differences in the larval fish community through space and time. For example, the abundance of temperate species in northern Baja California was relatively low when warm-water El Niño conditions prevailed in 1998 but increased during the cool-water La Niña period in 1999 and 2000. The results enhance knowledge of the community dynamics of fishes in an ecologically complex and commercially important region.

Digestion of pelagic Ctenophora and Cnidaria by fish

2003 ◽  
Vol 60 (7) ◽  
pp. 825-829 ◽  
Author(s):  
Mary N Arai ◽  
David W Welch ◽  
Adrienne L Dunsmuir ◽  
Melinda C Jacobs ◽  
Adrian R Ladouceur
Keyword(s):  
Chum Salmon ◽  
Salt Content ◽  
Stomach Contents ◽  
High Water ◽  
Organic Content ◽  
Oncorhynchus Keta ◽  
Energy Sources ◽  
Feeding Rates ◽  
Aequorea Victoria ◽  
Pleurobrachia Bachei

The diet of chum salmon (Oncorhynchus keta) can range from a primarily arthropod to a primarily gelatinous composition. Because no data exist for the digestion rates of gelatinous prey in any fish, it has not been possible to convert data on stomach contents to feeding rates. We measured rates of digestion to address this issue. In freely feeding age-0 chum salmon, the ctenophore Pleurobrachia bachei was digested almost completely within 1 h, whereas 70% of shrimp sections of similar mass remained after 5 h at 13°C. To examine the fast progress of digestion at smaller intervals, age-0 and age-1 fish were also force-fed with whole P. bachei or sections of the hydromedusa Aequorea victoria. These data emphasize the necessity of examining fish stomachs very quickly after capture. Although gelatinous organisms have high water and salt content relative to their organic content, given the rapid rates of digestion observed, coelenterates might rival arthropods as energy sources.

scholarly journals Individual trophic specialization in juvenile European seabass: implications for the management of a commercially important species

2019 ◽  
Vol 76 (6) ◽  
pp. 1784-1793 ◽  
Author(s):  
Matthew R D Cobain ◽  
Will Steward ◽  
Clive N Trueman ◽  
Antony Jensen
Keyword(s):  
Stable Isotope ◽  
Management Strategies ◽  
Stomach Contents ◽  
Fishing Effort ◽  
Trophic Specialization ◽  
Important Species ◽  
Stable Isotope Analyses ◽  
European Seabass ◽  
Commercially Important ◽  
Isotope Analyses

Abstract Individual differences in diet can play an important role defining a population's ecological niche and its role within food webs and habitats, but individual trophic specialization is rarely considered in a fisheries context. Stocks of European seabass, Dicentrarchus labrax, have declined in recent years, and policy has focused on managing fishing effort. Inshore nursery grounds represent a critical habitat in terms of recruitment to standing stocks, and improved understanding of the ecology of juvenile seabass at the level of the individual may assist the development of management strategies aimed at maximizing their survival and growth. We quantified levels of individual trophic specialization in juvenile seabass using stomach contents and stable isotope analyses at a monthly resolution over an annual cycle. We found significant, seasonally varying levels of individual specialization in stomach contents, with reduced specialization observed in the spring. This was corroborated by stable isotope analyses, where isotopic variance among seabass individuals was significantly higher compared to that in two other concurrently sampled, sympatric bentho-pelagic predators. Our findings suggest that juvenile seabass form trophic-generalist populations composed of specialized individuals. Considering variation in individual behaviours may improve management strategies aimed at protecting the vulnerable life stages of this commercially important species.

Trophic position scales positively with body size within but not among four species of rocky reef predators

2020 ◽  
Vol 640 ◽  
pp. 189-200 ◽  
Author(s):  
AM Olson ◽  
A Frid ◽  
JBQ dos Santos ◽  
F Juanes
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Morphometric Traits ◽  
Predator Species ◽  
Predatory Fishes ◽  
Average Size ◽  
Interspecific Comparisons ◽  
Large Predators

Intra- and interspecifically, larger-bodied predators generally occupy higher trophic positions (TPs). With widespread declines in large predators, there is a need to understand their size-based trophic roles to predict ecosystem-level responses. In British Columbia, Canada, we examined size-based trophic interactions between predatory fishes—3 rockfish species (genus Sebastes) and lingcod Ophiodon elongatus—and their prey, converting predator δ15N signatures to TP and analyzing stomach contents. Intraspecifically, TP scaled positively with predator length and gape width, but the rates of change varied by species. Interspecifically, TP did not scale positively with the observed mean sizes or known maximum sizes of species. Lingcod TP was lower than that of yelloweye and quillback rockfishes, which were 51 and 37%, respectively, smaller than lingcod. Yellowtail rockfish had the smallest average size, yet their mean TP did not differ significantly from that of lingcod. Neither species differences in some morphometric traits known to influence body size-TP relationships nor phylogenetic history explained these results. Most prey consumed were <20% of the predator’s size, which might partially explain the lack of a size-based trophic hierarchy among species. Currently, large size classes of rockfishes are being lost due to fisheries and perhaps climate-driven changes. Our findings on intraspecific size-TP relationships indicate that fishery removals of large individuals may diminish trophic structures. Interspecific comparisons of TP suggest that, along with size, species remain an important factor in understanding trophic dynamics. In addition, smaller-bodied predator species may have significant ecological roles to be considered in ecosystem-based fisheries management.

scholarly journals Induced sterility in fish and its potential and challenges for aquaculture and germ cell transplantation technology: a review

Biologia ◽  
2016 ◽  
Vol 71 (8) ◽  
Author(s):  
Amin Golpour ◽  
Mohammad Abdul Momin Siddique ◽  
Diógenes Henrique Siqueira-Silva ◽  
Martin Pšenička
Keyword(s):  
Germ Cell ◽  
Cell Transplantation ◽  
Large Scale ◽  
Hormonal Treatment ◽  
Important Species ◽  
Genetic Ablation ◽  
Germ Cell Transplantation ◽  
Commercially Important ◽  
Alternative Approaches ◽  
Hormone Signalling

AbstractInterest in reproductively sterile fish in aquaculture has prompted research into their production. Several methods are available for inducing sterility and optimizing its application in the global fishery industry. Sterilization can potentially be accomplished through irradiation, surgery, or chemical and hormonal treatment. Alternative approaches include triploidization, hybridization, and generation of new lines via advanced biotechnological techniques. Triploids of many commercially important species have been studied extensively and have been produced on a large scale for many years. Novel approaches, including disruption of gonadotropin releasing hormone signalling and genetic ablation of germ cells, have been developed that are effective in producing infertile fish but have the disadvantage of not being 100% reliable or are impractical for large-scale aquaculture. We review currently used technologies and recent advances in induction of sterility in fish, especially those intended for use in germ cell transplantation. Knowledge of the implications of these approaches remains incomplete, imposing considerable limitations.

Do changes in reef habitats influence relative predation risk on the juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875)?

Crustaceana ◽  
2015 ◽  
Vol 88 (7-8) ◽  
pp. 839-856 ◽  
Author(s):  
J. Hesse ◽  
J. A. Stanley ◽  
A. G. Jeffs
Keyword(s):  
Predation Risk ◽  
Spatial Scales ◽  
Spiny Lobster ◽  
Habitat Type ◽  
Small Spatial Scale ◽  
Important Species ◽  
Early Juvenile ◽  
Risk Of Predation ◽  
Jasus Edwardsii ◽  
Commercially Important

Kelp habitats are in decline in many temperate coastal regions of the world due to climate change and expansion of populations of grazing urchins. The loss of kelp habitat may influence the vulnerability to predators of the juveniles of commercially important species. In this study relative predation rates for kelp versus barren reef habitat were measured for early juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875), on the northeastern coast of New Zealand using tethering methods. Variation in assemblages of predators over small spatial scales appeared to be more important for determining the relative predation of lobsters, regardless of habitat type. Therefore, the assessment of relative predation risk to early juvenile lobsters between kelp and barren habitats will require more extensive sampling at a small spatial scale, as well as a specific focus on sampling during crepuscular and nocturnal periods when these lobsters are most at risk of predation.

Sign in / Sign up

Export Citation Format

Share Document