Adaptations for Aquatic Living by Carnivores

Estes, James A.

doi:10.1007/978-1-4613-0855-3_10

Cited by 41 publications

(65 citation statements)

References 136 publications

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“…Otters are semi-aquatic carnivores that acquired, through evolution, several morphological and physiological adaptations that allowed them to efficiently occupy aquatic environments (ESTES 1989). In spite of this, otters maintain a strong dependence on the terrestrial environment for some activities such as reproduction, parental care and resting (CHANIN 1985, ESTES 1989, KRUUK 1995.…”

Section: Discussionmentioning

confidence: 99%

“…In spite of this, otters maintain a strong dependence on the terrestrial environment for some activities such as reproduction, parental care and resting (CHANIN 1985, ESTES 1989, KRUUK 1995. For these reasons, most otter activities are carried out in the water and on banks along water bodies.…”

Section: Discussionmentioning

confidence: 99%

“…For these reasons, most otter activities are carried out in the water and on banks along water bodies. Thus, it is not surprising that the diet of the otters is composed mainly of aquatic (fish and crustaceans) or semi-aquatic items (frogs) (CHANIN 1985, ESTES 1989, KRUUK 1995.…”

Section: Discussionmentioning

confidence: 99%

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Seasonal and spatial differences in feeding habits of the Neotropical otter Lontra longicaudis (Carnivora: Mustelidae) in a coastal catchment of southeastern Brazil

Rheingantz¹,

Waldemarin²,

Rodrigues³

et al. 2011

Zoologia (Curitiba, Impr.)

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The diet of the Neotropical otter Lontra longicaudis (Olfers, 1818) is one of the best known aspects of its biology throughout its distribution range. However, most dietary studies have been undertaken during short time periods, making it difficult to identify temporal patterns in the feeding behavior of the species. The present study aimed to describe the diet of L. longicaudis in the lower region of the Mambucaba Catchment, state of Rio de Janeiro, Brazil, during a three year period, based on analyses of spraints (feces). The results show fish as the main prey item (frequency of occurrence, FO = 85.78%), as already described in previous studies. Crustaceans were the second main prey (FO = 70.67%), occurring in the spraints during the whole year, however presenting a higher frequency of occurrence than fish in samples collected during some months. Anurans were the third most important prey item (FO = 9.56%) and mammals, birds and reptiles were preyed upon only rarely (less than 4%). Fish and crustaceans were present in the diet of the species throughout the year and frogs were important mostly from June to August (dry season). This higher rate of predation on amphibians during the drier months was probably related to the decrease of the main prey

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Seasonal and spatial differences in feeding habits of the Neotropical otter Lontra longicaudis (Carnivora: Mustelidae) in a coastal catchment of southeastern Brazil

Rheingantz¹,

Waldemarin²,

Rodrigues³

et al. 2011

Zoologia (Curitiba, Impr.)

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“…The relationship between the age at which cranial development ceases and the age of sexual maturity was studied in species including spotted seals [20] and brown bears [24]. Sea otters reach sexual maturity later (males, 5-6 years; females, 2-5 years) [9,21] than they reach cranial maturity. Kenyon [18] suggested that young sea otters are more precocial than the young of either Lutra species or the giant river otter (Pteronura brasiliensis).…”

Section: Discussionmentioning

confidence: 99%

Age-Related Change and Allometry of Skull and Canine of Sea Otters, <i>Enhydra lutris</i>

Hattori

Burdin

Suzuki

et al. 2003

The Journal of Veterinary Medical Science

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ABSTRACT. Skulls and canines of 460 sea otters from Lopatka Cape, Kamchatka, were examined to assess development patterns, individual variation and sexual differences. An allometric formula was applied to morphometrical data, and the relative growth of each character to total length of skull was analyzed. In both sexes, most morphometrical characters ceased growth at about 2 years of age. Canine root length increased rapidly during the first year of life, while crown length decreased due to remarkable wear. There was large individual variation in the feeding and breathing/sniffing apparatus, while there was little variation in braincase size. There wer e sexual differences in most characteristics, although males and females showed similar growth patterns. The coronoid process of the mandible showed positive allometry in both sexes, and we attributed this finding to feeding habits. The fact that only male mastoids showed positive allometry may be due to the need for male otters to maintain a passing territory. KEY WORDS: allometry, Enhydra lutris, growth, morphology, skull.J. Vet. Med. Sci. 65(4): 439-447, 2003 The sea otter, Enhydra lutris, is a member of the Mustelidae, order Carnivora. It is highly adapted to the marine environment in a number of ways, including senses, feeding and behavior. Three subspecies of sea otters are commonly recognized: Asian (E. l. lutris), Alaskan (E. l. kenyoni) and southern sea otters (E. l. nereis) [2].Morphological studies of skulls of this species revealed geographic variation, and supported the above subspecies designations [3,18,29,36]. In most of these analyses, only adult specimens were used; the animals were considered adults if the basioccipital-basisphenoid suture was closed on the lower surface of the braincase [30]. Green [13] and Morejohn et al. [23] proposed criteria for relative age based on skull characters, tooth eruption and tooth wear. They used non-metric characters that indicate cessation of growth but not the age at which cessation occurred. The age of attainment of physical maturity is an important datum, because its variation can indicate changes in the nutritional condition of the population [25]. However, no detailed descriptions of age-related patterns of change have been available in sea otter skulls. Bodkin et al. [4] evaluated the accuracy and precision of using cementum layers of canine teeth to estimate sea otter age. They concluded that this method was sufficiently accurate for estimating age class distributions of relatively large samples.In this study, we used skull specimens to examine development of cranial structure in sea otters (E. l. lutris) in Lopatka Cape. We described growth over time, sexual differences and individual variation in the skulls and canines. Allometry was used to study relative growth of the different cranial components. We interpreted allometry coefficients as growth rates, although, in truth, they represented size rates. Discussion of our findings was based on functional grounds. MATERIALS AND METHODSWe analyzed 460...

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“…All of them have morphological and physiological adaptations to aquatic environments (Estes 1989). The Neotropical otter Lontra longicaudis (Mustelidae: Lutrinae) has a wide geographical distribution; it occurs from northern Mexico to Argentina and Uruguay, including most of the Neotropical region, except for Chile (Larivière 1999).…”

Section: Introductionmentioning

confidence: 99%

Feeding ecology of the Neotropical otter Lontra longicaudis in the Lower Arroio Grande River, southern Brazil

Souza

Bastazini

Colares

2013

An. Acad. Bras. Ciênc.

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The present study was based on the analysis of spraints (n = 294) collected between December 2005 and November 2007. The importance of each type of prey was determined by absolute and relative frequency. Niche breadth was also estimated. The results were reported as mean (± SD) of relative frequencies. Fish were the main prey found in spraints (57.8 ± 7.0%). Fish from Callichthyidae family were the main prey, followed by Cichlidae, the species Hoplias malabaricus and the family Characidae. The frequencies of other fish and taxa were lower than 13.9% (absolute frequency) and 5.6% (relative frequency). Despite significant seasonal variations, (P = 0.001), niche breadth values were low in all seasons (0.39 ± 0.11). Therefore, Lontra longicaudis presented a narrow niche breadth as a result of consistent fish predation. Based on these data, fish with rapid movement presenting territorial behavior and benthic fish with slow movements are the most consumed. Seasonal fluctuations are caused by the increase of secondary prey in the diet during some seasons.

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Adaptations for Aquatic Living by Carnivores

Cited by 41 publications

References 136 publications

Seasonal and spatial differences in feeding habits of the Neotropical otter Lontra longicaudis (Carnivora: Mustelidae) in a coastal catchment of southeastern Brazil

Seasonal and spatial differences in feeding habits of the Neotropical otter Lontra longicaudis (Carnivora: Mustelidae) in a coastal catchment of southeastern Brazil

Age-Related Change and Allometry of Skull and Canine of Sea Otters, <i>Enhydra lutris</i>

Feeding ecology of the Neotropical otter Lontra longicaudis in the Lower Arroio Grande River, southern Brazil

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