Ecological differences between two closely related morphologically similar benthic whitefish (Prosopium spilonotus and Prosopium abyssicola) in an endemic whitefish complex

2006 ◽  
Vol 63 (8) ◽  
pp. 1700-1709 ◽  
Author(s):  
Benjamen M Kennedy ◽  
Brett W Thompson ◽  
Chris Luecke
Keyword(s):  
Resource Use ◽  
Species Conservation ◽  
Distinct Group ◽  
Community Diversity ◽  
Lake Ecosystem ◽  
Ecosystem Structure ◽  
Lake Whitefish ◽  
Closely Related Species ◽  
Bear Lake ◽  
Ecological Differences

Identifying the differences in ecology between closely related species occupying the same environment contributes to our understanding of community diversity, ecosystem structure, and species conservation. Endemic Bear Lake whitefish (Prosopium abyssicola) and Bonneville whitefish (Prosopium spilonotus) are benthic, morphologically similar, and closely related, yet the extent of differential resource use remains poorly understood. To determine the ecological differences between these two species, we studied their seasonal distribution and diet in Bear Lake, Utah–Idaho. We used bottom-set gill nets to examine how catch of each species of whitefish varied in relation to depth and season (spring and summer). In both spring and summer, Bonneville whitefish dominated the shallower depths (5–30 m), whereas Bear Lake whitefish dominated the deeper depths (45–55 m). Bonneville whitefish ate a variety of benthic invertebrates, but mostly Chironomidae, whereas Bear Lake whitefish fed mostly on Ostracoda. These data describe a closely related morphologically similar, yet ecologically distinct group of whitefish in an ecoregion completely different from those studied before. These results indicated that each species has a very different role in the Bear Lake ecosystem. To conserve this unique fish assemblage, both shallow and deepwater habitats need to be protected.

scholarly journals Comparison of cnidae sizes between the two morphotypes of the giant Caribbean sea anemone Condylactis gigantea (Actiniaria: Actiniidae)

2018 ◽  
Vol 66 (3) ◽  
pp. 1055
Author(s):  
Ricardo Enrique González Muñoz ◽  
Carlos Hernández-Ortiz ◽  
Agustin Garese ◽  
Nuno Simões ◽  
Fabián Horacio Acuña
Keyword(s):  
Coral Reefs ◽  
Gulf Of Mexico ◽  
Related Species ◽  
Significant Variation ◽  
Caribbean Sea ◽  
Sea Anemone ◽  
Tropical Atlantic ◽  
Closely Related Species ◽  
Mexican Caribbean ◽  
Ecological Differences

The sea anemone Condylactis gigantea is an ecologically important member of the benthic community in coral reefs of the tropical Atlantic, and displays two morphotypes with respect to the color in their tentacular tips: the green tip morphotype and the pink/purple tip morphotype. Although some molecular and ecological differences have been found between these morphotypes, no other morphological distinctions have been reported, and currently both are still considered a single taxonomic species. In the present study, we perform an exploration on the variability in the size of cnidae between these two morphotypes and performed statistical analyses to compare the 10 categories of cnidae from specimens hosted in the Cnidarian Collection of Gulf of Mexico and Mexican Caribbean, of the Universidad Nacional Autónoma de México, which were previously collected in several coral reefs localities of the Yucatán Peninsula. Results reveal no significant variation in cnidae size between the two morphotypes, but significant variations were found within each morphotype. In addition, we update the composition of the cnidom of C. gigantea, and the utility of the size of cnidae to distinguish between morphotypes or closely related species is discussed.

TEMPORAL AND SPATIAL PATTERNS OF RESOURCE USE AMONG NICROPHORUS CARRION BEETLES (COLEOPTERA: SILPHIDAE) IN A SPHAGNUM BOG AND ADJACENT FOREST NEAR OTTAWA, CANADA

1992 ◽  
Vol 124 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Clifford W. Beninger ◽  
Stewart B. Peck
Keyword(s):  
Resource Use ◽  
Brood Size ◽  
Significant Positive Correlation ◽  
Mixed Forest ◽  
Resource Acquisition ◽  
Closely Related Species ◽  
Temporal And Spatial Patterns ◽  
Temporal And Spatial ◽  
Carrion Beetles ◽  
Sphagnum Bog

AbstractThis study examines reproductive resource acquisition and utilization among Nicrophorus carrion beetles (Coleoptera: Silphidae) in two different and adjacent habitats. The proportion of small carrion resource (dead mice, Mus musculus L.) used by Nicrophorus and other scavengers in a Sphagnum bog did not differ significantly from that used in a nearby forest. Among congeneric Nicrophorus, N. vespilloides Herbst reproduced on small carrion exclusively in the Sphagnum bog, whereas a closely related species, N. defodiens Mannerheim, reproduced only in the nearby mixed forest. Nicrophorus sayi Laporte, N. orbicollis Say, and N. tomentosus Weber were rarely associated with small carrion resource in the bog, and reproduced primarily in the forest during the spring, summer, and fall, respectively. A significant positive correlation between brood size and weight of larval carrion resource was found for N. vespilloides.

Status, Distribution, and Conservation of Native Freshwater Fishes of Western North America

2007 ◽  
Keyword(s):  
North America ◽  
Reliable Method ◽  
State University ◽  
Lake Whitefish ◽  
Utah State University ◽  
Bottom Trawling ◽  
Bear Lake ◽  
Gill Net ◽  
Catch Rates ◽  
Average Catch

ABSTRACT Populations of the four Bear Lake endemic species, Bonneville cisco <em>Prosopium gemmifer</em>, Bonneville whitefish <em>P. spilonotus</em>, Bear Lake whitefish <em>P. abyssicola</em>, and Bear Lake sculpin <em>Cottus extensus</em>, were monitored by Utah Division of Wildlife Resources and/or Utah State University. Bonneville cisco populations have been monitored annually since 1990 using hydroacoustic sampling. The population has ranged from 1.9 to 9.7 million fish. Because no reliable method was available to determine whitefish species identification prior to 1999, the whitefish population was monitored from 1973 to 1998 by lumping the catches of both species and referring to them as the “whitefish complex.” In 1999, the Utah Division of Wildlife Resources began recording the percentage of gill-net catch comprised by Bonneville and Bear Lake whitefish. Bonneville whitefish comprised between 84% and 94% of the gill-net catch while Bear Lake whitefish comprised between 6% and 16%. Relative abundance of Bear Lake sculpin was monitored biennially since 1998 using catch rates from bottom trawling. Average catch per 20-min trawl at both the top and bottom of the thermocline at three different sites ranged from 37 fish to 79 fish.

scholarly journals Fisheries impacts on lake ecosystem structure in the context of a changing climate and trophic state

2017 ◽  
Author(s):  
Tiina Nõges ◽  
Orlane Anneville ◽  
Jean Guillard ◽  
Juta Haberman ◽  
Ain Järvalt ◽  
...  
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Scale Effects ◽  
Trophic Levels ◽  
Interactive Effects ◽  
Phosphorus Loading ◽  
Lake Ecosystem ◽  
Ecosystem Structure ◽  
Top Down ◽  
Lake Basins

<p>Through cascading effects within lake food webs, commercial and recreational fisheries may indirectly affect the abundances of organisms at lower trophic levels, such as phytoplankton, even if they are not directly consumed. So far, interactive effects of fisheries, changing trophic state and climate upon lake ecosystems have been largely overlooked. Here we analyse case studies from five European lake basins of differing trophic states (Lake Võrtsjärv, two basins of Windermere, Lake Geneva and Lake Maggiore) with long-term limnological and fisheries data. Decreasing phosphorus concentrations (re-oligotrophication) and increasing water temperatures have been reported in all five lake basins, while phytoplankton concentration has decreased only slightly or even increased in some cases. To examine possible ecosystem-scale effects of fisheries, we analysed correlations between fish and fisheries data, and other food web components and environmental factors. Re-oligotrophication over different ranges of the trophic scale induced different fish responsesIn the deeper lakes Geneva and Maggiore, we found a stronger link between phytoplankton and planktivorous fish and thus a more important cascading top-down effect than in other lakes. This connection makes careful ecosystem-based fisheries management extremely important for maintaining high water quality in such systems. We also demonstrated that increasing water temperature might favour piscivores at low phosphorus loading, but suppresses them at high phosphorus loading and might thus either enhance or diminish the cascading top-down control over phytoplankton with strong implications for water quality.</p>

Overcoming human obstacles to conservation of recreational fishery resources, with emphasis on central Europe

2006 ◽  
Vol 33 (1) ◽  
pp. 46-59 ◽  
Author(s):  
ROBERT ARLINGHAUS
Keyword(s):  
Central Europe ◽  
Resource Use ◽  
Systems Approach ◽  
Resource Conservation ◽  
Ecosystem Structure ◽  
Recreational Fisheries ◽  
Fishery Resource ◽  
Fisheries Science ◽  
Recreational Fishery ◽  
Institutional Linkages

Recreational fisheries are the dominant or sole user of many coastal and most inland fish stocks in industrialized societies. Recreational angling can negatively affect fish populations, but appropriate management approaches to address these impacts are often lacking. Overall, privately-governed European recreational fisheries systems offer suitable conditions to reconcile resource use with resource conservation because access restriction is possible, decision-making structures are simple and management scales are small. This increases the hope that the race to fish may be less pronounced than in open-access commercial fisheries. To achieve harmony between use and conservation values, a thorough understanding of the human dimension is paramount, yet approaches including this are underrepresented in contemporary recreational fisheries science and management. Based on theoretical considerations, literature review and personal experiences, this paper presents key human obstacles to the reconciliation of recreational fishery resource use and resource conservation, with emphasis on private fishing rights regimes of central Europe. Nine obstacles are identified: (1) lack of social priority; (2) lack of integrated approaches; (3) lack of cooperative institutional linkages; (4) lack of systems thinking; (5) lack of research and monitoring; (6) lack of shared values and dominance of stereotyped perceptions; (7) lack of consideration for regional fish-angler dynamics; (8) lack of objective communication of scientific findings; and (9) lack of critical self-reflection among individual anglers. Potential solutions to overcome the identified constraints briefly discussed include: (1) evaluation of the socioeconomic benefits of angling; (2) rehabilitation of ecosystem structure and function on larger scales; (3) facilitation of structured cooperation between stakeholders and management units; (4) application of complex systems approach; (5) increased funding for long-term monitoring; (6) fostering of common values of different stake-holders; (7) active adaptive management of angling effort on regional scales; (8) intensified communication of research findings; and (9) conviction of anglers to meet personal targets by more restrictive regulations. Increasing research and management efforts related to the social component of recreational fisheries will improve reconciliation of resource use and resource conservation in traditional recreational fisheries management. It is a matter of societal values whether it is judged necessary to do so on a broader scale.

scholarly journals Selection in response to community diversity alters plant performance and functional traits

2017 ◽  
Author(s):  
Sofia J. van Moorsel ◽  
Marc W. Schmid ◽  
Terhi Hahl ◽  
Debra Zuppinger-Dingley ◽  
Bernhard Schmid
Keyword(s):  
Rapid Evolution ◽  
Species Conservation ◽  
Functional Trait ◽  
Community Diversity ◽  
Plant Performance ◽  
Conservation Practice ◽  
Grassland Species ◽  
Selection History ◽  
Species Mixtures ◽  
Biodiversity Effects

In grassland biodiversity experiments the positive biodiversity−ecosystem functioning relationship generally increases over time. However, we know little about the underlying short-term evolutionary processes. Using five plant species selected for twelve years in a biodiversity experiment in mixture or monoculture and plants without such a selection history, we assessed whether differential selection altered productivity, biodiversity effects, and functional trait differences within newly assembled monocultures and 2-species mixtures. Plants without past community selection history produced the lowest assemblage biomass and showed the weakest biodiversity effects. In newly assembled mixtures, plants with a selection history in mixtures produced more biomass than plants with a monoculture selection history. Biodiversity effects were generally positive and differed significantly between selection histories. However, contrary to our expectations, biodiversity effects were not stronger for mixture-type plants. Biodiversity effects were influenced by both trait differences between plants and community-weighted means, but these relationships were mostly independent of selection history. Our findings suggest that twelve years of selection history in monocultures or species mixtures differentiated plants of each species into monoculture-and mixture-types. Such rapid evolution of different community-types within grassland species and its effect on ecosystem services and functioning are likely to be important for species conservation practice.

Serial introductions modify a trophic cascade and partially mitigate changes in lake ecosystem structure

2019 ◽  
Vol 38 (3) ◽  
pp. 642-653
Author(s):  
David C. Richardson ◽  
Emma C. Bruno ◽  
Hailee L. Edwards ◽  
Dejea M. Green ◽  
Anthony J. Hollander ◽  
...  
Keyword(s):  
Trophic Cascade ◽  
Lake Ecosystem ◽  
Ecosystem Structure

Spatial and temporal variation of maturation schedules of lake whitefish (Coregonus clupeaformis) in the Great Lakes

2008 ◽  
Vol 65 (10) ◽  
pp. 2157-2169 ◽  
Author(s):  
Hui-Yu Wang ◽  
Tomas O. Höök ◽  
Mark P. Ebener ◽  
Lloyd C. Mohr ◽  
Philip J. Schneeberger
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Spatial And Temporal Variation ◽  
Ecosystem Structure ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Adaptive Responses ◽  
Fish Stocks ◽  
Ecosystem Changes ◽  
Plastic Responses

Fish maturation schedules vary greatly among systems and over time, reflecting both plastic and adaptive responses to ecosystem structure, physical habitats, and mortality (natural and fishing). We examined maturation schedules of commercially exploited lake whitefish ( Coregonus clupeaformis ) in the Laurentian Great Lakes (Lakes Michigan, Huron, and Superior) by estimating ages and lengths at 50% maturity, age-specific maturity ogives (age-specific probability of being mature), and probabilistic maturation reaction norms (PMRNs; a metric that accounts for effects of growth and mortality). Collectively, these estimates indicated variation in maturation schedules between sexes (i.e., males tend to mature at younger ages and shorter lengths than females) and among systems (midpoint estimates of PMRNs were smallest for Lake Michigan fish, intermediate for fish in the main basin of Lake Huron, and largest for fish in Lake Huron’s Georgian Bay and Lake Superior). Temporally, recent increases in age at 50% maturity in Lakes Huron and Michigan may primarily reflect plastic responses to decreased growth rates associated with ecosystem changes (e.g., declines of the native amphipod, Diporeia spp.). As plastic and adaptive changes in maturation schedules of fish stocks may occur simultaneously and require different management considerations, we recommend the concomitant analysis of multiple maturation indices.

scholarly journals Male–only care and classical polyandry in birds: phylogeny, ecology and sex differences in remating opportunities

2002 ◽  
Vol 357 (1419) ◽  
pp. 283-293 ◽  
Author(s):  
I. P. F. Owens
Keyword(s):  
Sex Differences ◽  
Related Species ◽  
Egg Size ◽  
Breeding Systems ◽  
Female Size ◽  
Huge Number ◽  
Closely Related Species ◽  
Significant Difference ◽  
Low Rate ◽  
Ecological Differences

It has been argued recently that the combination of male–only parental care and classical polyandry in birds is the most interesting and yet the least understood of all avian breeding systems. Despite a huge number of hypotheses, careful comparative analyses have repeatedly failed to identify consistent ecological differences between species showing male–only care and closely related species showing other patterns of care. This has led to the suggestion that such analyses fail because the crucial differences are between ancient lineages rather than between closely related species. Here, therefore, I use comparisons between families to test three well–known hypotheses: that male–only care is associated with: (i) a low rate of fecundity; (ii) large egg size relative to female size; or (iii) female–biased opportunities for remating. Families showing male–only care do not differ from families showing female–only care with respect to rate of fecundity or relative egg size. There is, however, a significant difference between these two groups of families with respect to an index of remating opportunities, nesting density. Families showing female–only care nest at high density, while those showing male–only care nest at very low density. This is one of the first times a consistent ecological correlate has been identified for male–only care in birds. It suggests that female–only care arises (or persists) in families where remating opportunities are abundant for both sexes, whereas male–only care arises (or persists) in families where remating opportunities are rare for both sexes and particularly scarce for males. This in turn suggests that sex differences in remating opportunities are the key ecological factor in determining male–only care and classical polyandry in birds.

Lake Shira, a Siberian salt lake: ecosystem structure and function

1999 ◽  
Vol 8 (3) ◽  
pp. 211-232 ◽  
Author(s):  
Tatyana A. Zotina ◽  
Alexander P. Tolomeyev ◽  
Nadezhda N. Degermendzhy
Keyword(s):  
Salt Lake ◽  
Structure And Function ◽  
Lake Ecosystem ◽  
Ecosystem Structure ◽  
Lake Shira ◽  
And Function ◽  
Ecosystem Structure And Function
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