The Effects of Body Size and Environmental Temperatures on Swimming Efficiency in Marine Mammals: Guidelines for Novel Underwater Propulsive Systems

2001 ◽  
Author(s):  
Terrie M. Williams
Keyword(s):  
Body Size ◽  
Marine Mammals ◽  
Swimming Efficiency ◽  
Environmental Temperatures

Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

scholarly journals Resurgence of an apex marine predator and the decline in prey body size

2019 ◽  
Vol 116 (52) ◽  
pp. 26682-26689 ◽  
Author(s):  
Jan Ohlberger ◽  
Daniel E. Schindler ◽  
Eric J. Ward ◽  
Timothy E. Walsworth ◽  
Timothy E. Essington
Keyword(s):  
Life History ◽  
Body Size ◽  
Chinook Salmon ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Size Structure ◽  
Economic Value ◽  
Killer Whales ◽  
Selective Predation ◽  
Marine Predator

In light of recent recoveries of marine mammal populations worldwide and heightened concern about their impacts on marine food webs and global fisheries, it has become increasingly important to understand the potential impacts of large marine mammal predators on prey populations and their life-history traits. In coastal waters of the northeast Pacific Ocean, marine mammals have increased in abundance over the past 40 to 50 y, including fish-eating killer whales that feed primarily on Chinook salmon. Chinook salmon, a species of high cultural and economic value, have exhibited marked declines in average size and age throughout most of their North American range. This raises the question of whether size-selective predation by marine mammals is generating these trends in life-history characteristics. Here we show that increased predation since the 1970s, but not fishery selection alone, can explain the changes in age and size structure observed for Chinook salmon populations along the west coast of North America. Simulations suggest that the decline in mean size results from the selective removal of large fish and an evolutionary shift toward faster growth and earlier maturation caused by selection. Our conclusion that intensifying predation by fish-eating killer whales contributes to the continuing decline in Chinook salmon body size points to conflicting management and conservation objectives for these two iconic species.

scholarly journals Examining predator–prey body size, trophic level and body mass across marine and terrestrial mammals

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142103 ◽  
Author(s):  
Marlee A. Tucker ◽  
Tracey L. Rogers
Keyword(s):  
Community Structure ◽  
Body Size ◽  
Body Mass ◽  
Marine Environment ◽  
Trophic Level ◽  
Marine Mammals ◽  
Trophic Position ◽  
Trophic Levels ◽  
Predator Prey ◽  
Terrestrial Mammals

Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial ( n = 51) and marine ( n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities.

Structure and concentrating ability of the mammalian kidney: correlations with habitat

1996 ◽  
Vol 271 (1) ◽  
pp. R157-R179 ◽  
Author(s):  
C. A. Beuchat
Keyword(s):  
Body Size ◽  
Marine Mammals ◽  
Functional Dependence ◽  
Urine Osmolality ◽  
Urine Concentration ◽  
Thick Ascending Limb ◽  
Loop Of Henle ◽  
Central Tenet ◽  
Absolute Length ◽  
Urinary Concentrating Ability

Mammals with relatively long loops of Henle for their body size tend to have greater than average urinary concentrating ability, but the relationship between urine osmolality (Uosm) and absolute length of the loop of Henle (generally estimated as medullary thickness) is neither proportional nor direct. Uosm is independent of the thickness of the outer medulla (corresponding to the length of the medullary thick ascending limb), which scales similarly with body mass in animals from mesic, arid, and freshwater environments. After adjustment for the effect of body size, there is a significant relationship between the thickness of the inner medulla (corresponding to length of the thin ascending limb) and concentrating ability, but only in species from mesic environments; for these, the thickness of the inner medulla accounts for only 16% of the interspecific variability in Uosm. In marine mammals, both the cortex and medulla are surprisingly thin, yet these animals produce very concentrated urine for their size. A functional dependence of urinary concentrating ability on the length of the loop of Henle is a central tenet of countercurrent multiplier theory, but the correlation of maximum urine concentration with loop length is weak at best and largely reflects the influence of the thin ascending limb.

Energy losses due to routine and feeding metabolism in young-of-the-year juvenile Atlantic cod (Gadus morhua)

2003 ◽  
Vol 60 (8) ◽  
pp. 929-937 ◽  
Author(s):  
Myron A Peck ◽  
Lawrence J Buckley ◽  
David A Bengtson
Keyword(s):  
Body Size ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Effect Of Temperature ◽  
Energy Losses ◽  
The North ◽  
A Value ◽  
Different Temperatures ◽  
Body Sizes ◽  
Environmental Temperatures

We examined the effects of body size (3–13 cm total length) and temperature (4.5, 8.0, 12.0, and 15.5 °C) on routine (RR) and feeding (RSDA) energy losses by laboratory-reared, young-of-year juvenile Atlantic cod (Gadus morhua). The magnitude of the effect of temperature on RR, expressed via the Q10, was nonlinear. Q10 values were greatest at temperatures between 4.5 and 8.0 °C and were lowest between 8.0 and 15.5 °C, with larger fish tending to exhibit the greatest change in RR irrespective of the temperature combination. Energy losses resulting from RSDA were ~4% of consumed energy, a value less than half that estimated for larger, year-1+ juvenile cod fed similar-sized rations. Data from this and other studies were combined to generate an equation estimating routine energy loss at different temperatures and body sizes for cod. The equation describes RR over the eight orders of magnitude difference in body size from young larvae to adults within a range of environmental temperatures experienced by this species on Georges Bank and other areas in the North Atlantic.

scholarly journals Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans

2006 ◽  
Vol 274 (1609) ◽  
pp. 471-477 ◽  
Author(s):  
Katsufumi Sato ◽  
Yutaka Watanuki ◽  
Akinori Takahashi ◽  
Patrick J.O Miller ◽  
Hideji Tanaka ◽  
...  
Keyword(s):  
Body Size ◽  
Marine Mammals ◽  
Breath Hold ◽  
Sperm Whales ◽  
Stroke Frequency ◽  
Scaling Relationship ◽  
Theoretical Predictions ◽  
Large Animals ◽  
Free Ranging ◽  
Stroke Cycle

It is obvious, at least qualitatively, that small animals move their locomotory apparatus faster than large animals: small insects move their wings invisibly fast, while large birds flap their wings slowly. However, quantitative observations have been difficult to obtain from free-ranging swimming animals. We surveyed the swimming behaviour of animals ranging from 0.5 kg seabirds to 30 000 kg sperm whales using animal-borne accelerometers. Dominant stroke cycle frequencies of swimming specialist seabirds and marine mammals were proportional to mass −0.29 ( R 2 =0.99, n =17 groups), while propulsive swimming speeds of 1–2 m s −1 were independent of body size. This scaling relationship, obtained from breath-hold divers expected to swim optimally to conserve oxygen, does not agree with recent theoretical predictions for optimal swimming. Seabirds that use their wings for both swimming and flying stroked at a lower frequency than other swimming specialists of the same size, suggesting a morphological trade-off with wing size and stroke frequency representing a compromise. In contrast, foot-propelled diving birds such as shags had similar stroke frequencies as other swimming specialists. These results suggest that muscle characteristics may constrain swimming during cruising travel, with convergence among diving specialists in the proportions and contraction rates of propulsive muscles.

A revision of the genus Orthosplanchnus Odhner, 1905 with consideration of the genera Odhneriella Skriabin, 1915 and Hadwenius Price, 1932 (Digenea: Campulidae)

1989 ◽  
Vol 67 (5) ◽  
pp. 1268-1278 ◽  
Author(s):  
Ann M. Adams ◽  
Robert L. Rausch
Keyword(s):  
Body Size ◽  
Marine Mammals ◽  
Type Species ◽  
The Other ◽  
Clinal Variation ◽  
Erignathus Barbatus ◽  
Bearded Seals

The present paper concerns digeneans of the subfamilies Odhneriellinae Yamaguti, 1958 and Orthosplanchninae Yamaguti, 1958, family Campulidae Odhner, 1926, and is based mainly on specimens collected since 1949 from marine mammals from seas bordering Alaska. Odhneriella rossica Skriabin, 1915, type species of the subfamily Odhneriellinae, is transferred to the genus Orthosplanchnus Odhner, 1905. Odhneriellinae thus becomes a synonym of Orthosplanchninae, which includes three genera: Orthosplanchnus Odhner, 1905 (syn. Odhneriella Skriabin, 1915); Hadwenius Price, 1932 (syn. Leucasiella Krotov and Deliamure, 1952); and Oschmarinella Skriabin, 1947. Seven species are retained in Orthosplanchnus: O. arcticus Odhner, 1905; O. fraterculus Odhner, 1905; Orthosplanchnus rossicus (Skriabin, 1915) n.comb. (syn. Odhneriella rossica Skriabin, 1915); O. pygmaeus Iurakhno, 1967; O. albamarinus Treshchev, 1968; O. oculatus Iurakhno, 1969; and O. antarcticus Kurochkin and Nikol'skii, 1972 (syn. O. weddelli Beverley-Burton, 1972). Orthosplanchnus elongatus Ozaki, 1935 is transferred to the genus Hadwenius, as is Odhneriella subtilus (A. S. Skriabin, 1959); O. sudarikovi Treshchev, 1966, excluded from Orthosplanchnus, is of uncertain generic allocation. Orthosplanchnus rossicus is redescribed, and descriptions are provided for the other species recognized in the genus. Variation in O. arcticus from various hosts is considered; in bearded seals, Erignathus barbatus (Erxleben), clinal variation was apparent in O. arcticus, with body size increasing from north to south.

Bergmann's rule in the oceans? Temperature strongly correlates with global interspecific patterns of body size in marine mammals

2016 ◽  
Vol 25 (10) ◽  
pp. 1206-1215 ◽  
Author(s):  
Erik Joaquín Torres-Romero ◽  
Ignacio Morales-Castilla ◽  
Miguel Á. Olalla-Tárraga
Keyword(s):  
Body Size ◽  
Marine Mammals ◽  
Bergmann’S Rule ◽  
Bergmann's Rule
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