scholarly journals Differentiating morpho-functional patterns of the five most common deep-sea benthic anglerfishes (Lophiiformes) from Andaman and Nicobar Islands (eastern Indian Ocean)

2020 ◽  
Vol 84 (4) ◽  
pp. 369-384
Author(s):  
Meleppura Rajeeshkumar ◽  
Kannamkulathil Vijayan Aneesh Kumar ◽  
José Luís Otero-Ferrer ◽  
Antoni Lombarte ◽  
Manjebrayakath Hashim ◽  
...  
Keyword(s):  
Deep Sea ◽  
Niche Overlap ◽  
Functional Study ◽  
Ecological Niches ◽  
Fish Length ◽  
Dorsal Margin ◽  
Ecological Specialization ◽  
Morphological Pattern ◽  
Eye Size ◽  
Nocturnal Feeding

Anglerfishes are widely distributed from shallow to deep-water habitats occupying different ecological niches. To explain this adaptability, we performed a morpho-functional study on common benthic anglerfishes inhabiting the Indian deep-sea waters. Sensory capabilities of species were examined using the morphology and morphometry of sagitta otoliths (related to detection sound and hearing) and eye size (related to visual communication). We also performed an analysis of the degree of functional niche overlap using fish body traits to understand the coexistence of species. Otoliths showed a morphological pattern similar to that of other anglerfishes: an archaesulcoid sulcus acusticus and variability in the irregularity of the dorsal margin. This last feature affected the allometric relationships between the otolith morphometry and fish length, as well as the otolith relative sizes of each species. The findings suggested that bigger otoliths are associated with the increase of depth distribution of species up to 1000 m, from which it decreases. Our hypothesis is that anglerfishes with irregular otolith shapes could be linked to more nocturnal feeding behaviour because they were characterized by greater eye sizes. The results also indicated interspecific significant differences in functional traits providing a low niche overlap. Therefore, our study supports the hypothesis of an environmental and ecological specialization of benthic anglerfishes.

Functional approach reveals low niche overlap among common deep-sea fishes from the south-eastern Arabian Sea

2017 ◽  
Vol 119 ◽  
pp. 16-23 ◽  
Author(s):  
K.V. Aneesh Kumar ◽  
V.M. Tuset ◽  
Hashim Manjebrayakath ◽  
K.S. Sumod ◽  
M. Sudhakar ◽  
...  
Keyword(s):  
Deep Sea ◽  
Arabian Sea ◽  
Niche Overlap ◽  
Functional Approach ◽  
The South ◽  
South Eastern ◽  
Eastern Arabian Sea

Two new species of Pseudoscopelus (Teleostei: Chiasmodontidae), with a new diagnosis for the genus

Zootaxa ◽  
2007 ◽  
Vol 1605 (1) ◽  
pp. 33-46 ◽  
Author(s):  
MARCELO R.S. MELO ◽  
H. J. WALKER ◽  
CYNTHIA KLEPADLO
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Dorsal Margin ◽  
Dorsal Edge ◽  
As Species ◽  
Infraorbital Canal ◽  
Two New Species ◽  
New Diagnosis ◽  
Sea Fish ◽  
The Western Pacific

Two new species of the deep-sea fish genus Pseudoscopelus are described, P. lavenbergi from the eastern Pacific, and P. bothrorrhinos from the western Pacific and Indian Oceans. A new diagnosis for Pseudoscopelus based on two synapomorphies is proposed: the dorsal margin of the orbit is formed by infraorbital 6; the last pore of the infraorbital canal is on the dorsal edge of the orbit, anterior to the middle of the pupil. Twelve species of the genus are considered valid, with P. microps confirmed as a junior synonym of P. altipinnis, and P. stellatus regarded as species inquerida.

High niche overlap between two successfully coexisting pairs of Lake Malawi cichlid fishes

2009 ◽  
Vol 66 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Christopher H. Martin ◽  
Martin J. Genner
Keyword(s):  
Resource Availability ◽  
Niche Overlap ◽  
Lake Malawi ◽  
Resource Scarcity ◽  
Ecological Niches ◽  
Similar Species ◽  
Dietary Overlap ◽  
Resource Abundance ◽  
Species Pairs ◽  
Foraging Rate

Many species in high-diversity assemblages appear to coexist in similar ecological niches. It has been proposed that interspecific resource partitioning in these assemblages may only occur during periods of resource scarcity. We tested this hypothesis by measuring resource abundance, dietary overlap, foraging rate, and territoriality in a Lake Malawi rock cichlid assemblage over a period of 1 year. Our study examined two pairs of morphologically similar species, with each pair comprising one native species and one invader species that has successfully established after being translocated from another region of the lake. All four species changed their diet and foraging rate in response to seasonal variation in resource abundance. However, dietary overlap within both species pairs remained high in all seasons and was not influenced by resource availability. Similarly, territoriality did not decline during periods of low resource availability, suggesting no decrease in the strength of interspecific competition. These data suggest that these species pairs are successfully coexisting despite substantial niche overlap during resource scarcity. Thus, the coexistence of species within this radiation may not depend on the evolution of divergent resource use patterns.

The Reproductive Biology of the Deep-Sea Asteroid Bathybiaster Vexillifer

1982 ◽  
Vol 62 (1) ◽  
pp. 57-69 ◽  
Author(s):  
P. A. Tyler ◽  
S. L. Pain ◽  
J. D. Gage
Keyword(s):  
Shallow Water ◽  
Reproductive Biology ◽  
Deep Sea ◽  
Reproductive Strategies ◽  
Ecological Niches ◽  
Physico Chemical ◽  
Males And Females ◽  
Planktotrophic Larvae ◽  
Shallow Water Species ◽  
Water Species

INTRODUCTIONThe reproductive biology of asteroids from a wide variety of ecological niches has been examined (Farmanfarmaian et al. 1958; Cognetti & Delavault, i962;Pearse, 1965; Chia, 1968; Crump, 1971; Jangoux & Vloebergh, 1973; Worley, Franz & Hendler, 1977; Barker, 1979; Shick, Taylor & Lamb, 1981). Most of the species within this class appear to show some degree of seasonal reproductive synchrony with very few species showing aseasonal reproduction (Shick et al. 1981). Although the seasonally reproducing asteroids show a wide variety of reproductive strategies, from planktotrophic larvae to direct development, they all occur in relatively shallow water and are thus subject to the seasonal fluctuations of the physico-chemical environment. Only two shallow-water species, Ctenodiscus crispatus (Shick et al. 1981) and Patiriella exigua (Lawson-Kerr & Anderson, 1978), have aseasonal reproduction in both males and females. However, the deep sea is the only major environment in the world's ocean for which we have no data for the reproductive cycle of asteroids.

scholarly journals Ecological niche overlap among species of the genus Zaluzania (Asteraceae) from the dry regions of Mexico

2020 ◽  
Vol 153 (3) ◽  
pp. 337-347
Author(s):  
Mario Ernesto Suárez-Mota ◽  
José Luis Villaseñor
Keyword(s):  
Ecological Niche ◽  
Potential Distribution ◽  
Area Under The Curve ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Niche Conservatism ◽  
Distribution Models ◽  
Closely Related Species ◽  
Environmental Pressures ◽  
Fundamental Niche

Background and aims – The hypothesis of ecological niche conservatism postulates that closely related species share ecologically similar environments; that is, they tend to maintain the characteristics of their fundamental niche over time. The objective of this study is to evaluate the similarity and equivalence of the ecological niches among species of the genus Zaluzania (Asteraceae), characteristic of the Mexican arid and semi-arid regions, to infer their potential niche conservatism. Methods – Based on critically reviewed herbarium occurrence data, potential distribution models for eight species of Zaluzania were generated using the Maxent algorithm. The overlap between potential distribution areas was then evaluated using equivalence and ecological niche parameters implemented in the ENMTools software; for this we quantified the degree of overlap and similarity between the niches using the equivalence (D) and similarity (I) parameters.Key results – The resulting models show that species display areas of high suitability along the Mexican dry regions, as well as overlapping heterogeneous values. All models showed high AUC (Area Under the Curve) values (> 0.8). The D and I values between each pair of species showed low values of overlap.Conclusions – Each species of the genus shows a fundamental niche distinct from their sister species. The genus thus offers an example of niche divergence among species, with each one adapting to different environmental pressures. Our results do not support the hypothesis of niche conservatism in the genus, suggesting that the species evolved in divergent environments.

scholarly journals Ecological Specialization and Overlap of Brachyramphus Murrelets in Prince William Sound, Alaska

The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 680-699
Author(s):  
Robert H. Day ◽  
Alexander K. Prichard ◽  
Debora A. Nigro
Keyword(s):  
Habitat Use ◽  
Habitat Type ◽  
Late Summer ◽  
Niche Overlap ◽  
Water Clarity ◽  
Turbid Water ◽  
Prince William Sound ◽  
Ecological Specialization ◽  
Marbled Murrelet ◽  
Marbled Murrelets

Abstract We compared habitat use and niche overlap in the closely related seabirds Kittlitz’s (Brachyramphus brevirostris) and Marbled (B. marmoratus) Murrelets in nearshore waters of Prince William Sound, Alaska, in 1996–1998, and examined the relationship between near shore habitat use and morphology of those two species. Within bays, the distribution of Kittlitz’s Murrelet groups diverged the most from randomness for the variables habitat type (preferring [i.e. using significantly more than what is available] glacial-affected and glacial-stream-affected habitats), distance to shore (preferring areas 51–100 m from shore), and water clarity (preferring highly turbid water), whereas the distribution of Marbled Murrelet groups diverged the most from randomness for the variables habitat type (preferring glacial-unaffected habitats), ice cover (preferring areas of no ice), and sea-surface temperature (SST) (preferring temperatures = 6°C). The probability of a group of birds being Kittlitz’s Murrelets was determined most strongly by water clarity. Kittlitz’s Murrelet groups were more common in the more heavily glaciated College and Harriman fjords than in the other two bays and more common in early and midsummer than in late summer; the reverse was true for Marbled Murrelet groups. Marbled Murrelet groups had the least niche overlap with Kittlitz’s Murrelet groups in water clarity, SST, and site, whereas Kittlitz’s Murrelets had the least overlap with Marbled Murrelets in habitat type and water clarity. Similarly, Kittlitz’s Murrelet groups occurred in water significantly more turbid than did Marbled Murrelet groups in two of four habitat types. Kittlitz’s Murrelets had eyes (as indicated by orbit diameter) that were significantly larger in proportional size than Marbled Murrelets. We propose that these two species are specialized for foraging in different water types, with specialization of the Kittlitz’s Murrelet for turbid water of glacial origin leading to optical specialization.

Four new deep-water flabelligerid species from Pacific Costa Rica (Annelida, Sedentaria, Flabelligeridae)

Zootaxa ◽  
2020 ◽  
Vol 4885 (4) ◽  
pp. 560-578
Author(s):  
SERGIO I. SALAZAR-VALLEJO
Keyword(s):  
Costa Rica ◽  
Deep Water ◽  
Deep Sea ◽  
Type Species ◽  
Anterior Margin ◽  
Single Type ◽  
Methane Seeps ◽  
Morphological Pattern ◽  
Fourth Species ◽  
Benthic Sampling

The discovery of four undescribed flabelligerid species from deep-water in Pacific Costa Rica resulted in the restriction of Diplocirrus Haase, 1915. As currently understood, Diplocirrus and Pherusa Oken, 1807 are separated after their morphological pattern. The species belonging in Diplocirrus have two types of branchiae, poorly developed cephalic cages and multiarticulate neurochaetae, whereas Pherusa species have branchiae of one type, well-developed cephalic cages and completely anchylosed neurochaetae. Benthic sampling and processing usually damage cephalic cages and if chaetae are completely broken, one could regard specimens without them, when they actually have it, but lost after sieving. Sampling using Alvin deep-sea submarine at methane seeps off Costa Rica resulted in some well-preserved specimens, and some of them fall between these two genera because they have well developed cephalic cages, and multiarticulate neurochaetae. Saphobranchia Chamberlin, 1919, with Stylarioides longisetosa von Marenzeller, 1890, as type species, is herein reinstated for some species previously included in Diplocirrus, restricted. The transferred species, including three ones newly described herein, have branchiae of a single type, long cephalic cage and body chaetae, and neurochaetae basally anchylosed and medially and distally articulated; some species currently included in Diplocirrus described from Arctic or deep water sediments are transferred into it. A key to identify all species in Saphobranchia, and another key to identify species in the restricted Diplocirrus are also included. The three new Saphobranchia species are S. canela n. sp., S. ilys n. sp. and S. omorpha n. sp. The fourth species belongs in Lamispina Salazar-Vallejo, 2014, and it is herein described as L. polycerata n. sp. after the presence of some long papillae along anterior margin of chaetiger 1. 

scholarly journals River dynamics and invasion: distribution patterns of native and invasive woody vegetation at the Río Negro, Argentina

2015 ◽  
Vol 2 (1) ◽  
pp. 45-57 ◽  
Author(s):  
Lisa K. Thomas ◽  
Eva Mosner ◽  
Ilona Leyer
Keyword(s):  
Niche Overlap ◽  
Ecological Niches ◽  
Life Stages ◽  
Riparian Ecosystems ◽  
Distribution Models ◽  
Potential Threat ◽  
Randomized Sampling ◽  
Rio Negro ◽  
Invasive Taxa ◽  
The Impact

AbstractSalicaceae are typical invaders of riparian ecosystems throughout the world and they have the potential to change much of the invaded habitats. Along Patagonian streams, riparian softwood forests composed of non-native Salicaceae are increasing in abundance, area and tree species diversity. Especially in the last decades, dense floodplain forests dominated by invasive willows and poplars and additionally Russian olive and tamarisk spread almost explosively e.g. along the Río Negro in northern Patagonia. This study focuses on the identification of ecological niches and niche overlaps of the native and invasive woody species in order to assess the impact on the native Salix humboldtiana Willd. Data on species (presence/ absence) and explanatory variables were gathered in the field using a grid-based, stratified-randomized sampling design. Different environmental variables were then related to species occurrence in different life stages (adult, juvenile, seedling) using habitat distribution models. In the final models, flood duration, the amount of gravel and the location (upper or middle river valley) were included to describe the probability of occurrence of native and invasive taxa. For all life stages, a strong niche overlap could be observed for S. humboldtiana and the invasive taxa with no remaining exclusive habitats indicating a potential threat to the native willow. The study contributes to a better understanding of Salicaceae invasion and its consequences for riparian ecosystems.

scholarly journals Trait‐based life strategies, ecological niches, and niche overlap in the nekton of the data‐poor Mediterranean Sea

2020 ◽  
Vol 10 (14) ◽  
pp. 7129-7144
Author(s):  
Martha Koutsidi ◽  
Catherine Moukas ◽  
Evangelos Tzanatos
Keyword(s):  
Mediterranean Sea ◽  
Niche Overlap ◽  
Ecological Niches ◽  
Life Strategies
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