Marine otters, Lontra felina , are found along the Pacific Coast from northern Peru south along the coast of Chile to the southern tip of South America. Lontra felina is also found in isolated populations in Argentina.
(Brack Egg, 1978; Brownell, 1978; Cabrera, 1957)
Biogeographic Regions: neotropical (Native ); pacific ocean (Native )
Peru south to Straits of Magellan
Lontra felina, otherwise known as marine otters or sea cats, is the smallest and most distinct species of the genus Lontra. The average total length of L. felina is 900 mm. The coat is dark on the back and on the sides, and paler ventrally. Marine otters have a short tail and fully webbed feet. They also have large vibrissae, stiff whisker-like hairs above the upper lip and at the corners of the mouth.
(Harris, 1968; van Zyll de Jong, 1972; Redford and Eisenberg, 1992; Lariviere, 1998)
Range mass: 3 to 5 kg.
Average mass: 4.5 kg.
Average length: 900 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Lontra felina is the only species of the genus Lontra that is found exclusively in marine habitats. Generally, marine otters inhabit areas with strong winds, heavy seas, and a high diversity of rock fishes, molluscs, and crustaceans. Lontra felina prefers to occupy areas with rocky outcroppings (often with caves high above the water and tunnels connecting the land and water). This species spendsmost of its time in the water, but does use the rocky shore areas in which it resides, especially during the breeding season.
"Outcroppings with large rocks contain more caves, harbor more prey, and offer better protection from predators" (Lariviere, 1998).
Perhaps because of their preference for rocky shores, marine otters have never been found along the sandy beaches of the Atlantic Patagonian coasts.
(Ostfeld et al., 1989; Castilla and Bahamondes, 1979; Lariviere, 1998)
Habitat Regions: temperate ; tropical ; terrestrial ; saltwater or marine
Aquatic Biomes: coastal
Other Habitat Features: intertidal or littoral ; caves
Habitat and Ecology
The marine otter diet is composed mostly of invertebrates, including crustaceans (decapods, shrimps, and crabs) and mollusks (bivalves and gastropods), and vertebrate prey, including fish from the families Blennidae, Cheilodactylidae, Gobiesocidae, and Pomacentridae, and occasionally birds and small mammals (Cabello 1978; Castilla and Bahamondes 1979; Ostfeld et al. 1989; Sielfeld 1990a). Along the Valdivian coast in the south of Chile the diet of marine otter consisted of 25 species; 52% (13/25) of the species identified were crustaceans, 40% (10/25) were fish, and 8% (2/25) were mollusks. Crustaceans were found in 78% of 475 spraints, 100% of 929 prey remains, and 90.8% of prey determined by direct observation, fish in 20% of spraints and 9.0% of prey determined by direct observation, and mollusks in 2% of spraints and 0.2% of prey determined by direct observation. Observed seasonal variation in prey availability was reflected in the otter diet. Fourteen prey species were trapped; 43% (6/14) were crustaceans and 57% (8/14) fish, crustaceans were 93% of 566 trapped individuals, fish 7%. L. felina showed opportunistic feeding behavior, selecting prey seasonally according to their availability rather than to their energy input (Medina et al. 2004).
Some analyses have found that fruits (Greigia sphacelata, Fascicularia bicolor) may also be consumed on occasion (Brownell 1978; Cabello 1978; Medina 1995). Marine otters may compete with gulls (Larus) and the South American sea lion (Otaria flavescens) for similar species of prey fish (Cabello 1978). The most important natural predator of the marine otter is the killer whale (Orcinus orca; Cabello 1978), but adults also may be killed by sharks (Parera 1996) and birds of prey may capture juveniles when on land (Cabello 1983).
The marine otter is most likely a monogamous species. Mating typically occurs during December or January (Caballo 1978) with gestation of 60-65 days (Housse 1953; Sielfield 1983). Parturition usually occurs from January to March. It takes place in a den or on shore between rocky outcroppings and vegetation. The litter size varies from two to four young, with two being observed most frequently. Young marine otters remain with their parents for approximately ten months. Adults transport their young by carrying them in their mouths or resting the young on their bellies as they swim on their backs. Both adults in the monogamous pair bring prey back to the den to feed their young (Parera 1996). When not breeding, marine otters are mostly solitary. The group size is seldom more than two to three individuals. Its activity pattern is generally diurnal, with peaks of activity noted in early morning, mid-afternoon, and evenings. Marine otters are much more agile in the water than on land.
The marine otter's diet mainly consists of invertebrates (including crustaceans and molluscs), fish, and occasionally, birds and small mammals. Periodically, fruits are also consumed. Marine otters spend 63 to 70% of their time catching and feeding on prey.
(Ostfeld et al., 1989; Castilla and Bahamondes, 1979; Lariviere, 1998)
Animal Foods: birds; mammals; eggs; mollusks; aquatic crustaceans; echinoderms; other marine invertebrates
Plant Foods: fruit
Primary Diet: carnivore (Eats non-insect arthropods)
Known prey organisms
Based on studies in:
Chile, central Chile (Littoral, Rocky shore)
This list may not be complete but is based on published studies.
- J. C. Castilla, Perspectivas de investigacion en estructura y dinamica de communidades intermareales rocosas de Chile Central. II. Depredadores de alto nivel trofico, Medio Ambiente 5(1-2):190-215, from p. 203 (1981).
Life History and Behavior
Perception Channels: tactile ; chemical
Lontra felina is most likely a monogamous species. Mating typically occurs during December or January.
After a gestation period of 60 to 65 days, parturition usually occurs from January to March. It takes place in a den or on shore between rocky outcroppings and vegetation. The litter size varies from two to four young, with two being observed most frequently.
Young marine otters remain with their parents for approximately ten months. Adults transport their young by carrying them in their mouths or resting the young on their bellies as they swim on their backs. Both adults in the monogamous pair bring prey back to the den to feed their young.
(Ostfeld et al., 1989; Housse, 1953; Lariviere, 1998)
Breeding interval: These animals breed once annually.
Breeding season: Breeding occurs in December and January.
Range number of offspring: 2 to 4.
Average number of offspring: 2.
Range gestation period: 60 to 65 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous
L. felina is classified as endangererd by the IUCN and is listed in CITES in Appendix I. Habitat destruction, pollution, and illegal poaching have resulted in the declining population of this species. The current remaining population is estimated to be less than 1000 individuals.
(Castilla and Bahamondes, 1979; Lariviere, 1998)
CITES: appendix i
IUCN Red List of Threatened Species: endangered
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1994Vulnerable(Groombridge 1994)
- 1990Vulnerable(IUCN 1990)
- 1988Vulnerable(IUCN Conservation Monitoring Centre 1988)
- 1986Vulnerable(IUCN Conservation Monitoring Centre 1986)
- 1982Vulnerable(Thornback and Jenkins 1982)
Date Listed: 06/14/1976
Lead Region: Foreign (Region 10)
Where Listed: Peru south to Straits of Magellan
Population location: Peru south to Straits of Magellan
Listing status: E
For most current information and documents related to the conservation status and management of Lontra felina, see its USFWS Species Profile
In addition to hunting, marine otters may be killed incidentally by fishing activities (Brownell 1978), or persecuted and killed directly for alleged damage to local fish, bivalves, and shrimp populations (Miller et al. 1983; Redford and Eisenberg 1992). Fishery overexploitation of crabs and mollusks in some regions of the coast may be a major threat to otters due to the reduction of available food sources.
Relevance to Humans and Ecosystems
Marine otters have been captured and killed for their competition with humans for prey. Fisheries suspect that marine otters cause damage to local fish, shrimp, and bivalve populations.
(Larivier, 1998; Redford and Eisenberg, 1992)
Marine otters are often illegally captured and killed for their pelts, which are used for footwear, especially boots. While illegal, harvesting marine otters is a fairly frequent occurrence in Chile, as the potential of being caught and fined is low.
Lontra felina is also sometimes trained, domesticated, and used by fisherman. Young marine otters are easily bottle-fed, and adults seem to adapt well to freshwater ponds and food items given to other domestic animals. Play behavior has also been observed between L. felina and other domesticated animals.
(Macdonald and Mason, 1990; Lariviere, 1998)
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The marine otter, Lontra felina, is a rare and poorly known South American mammal of the weasel family (Mustelidae). The scientific name means "otter cat", and in Spanish, the marine otter is also often referred to as gato marino: "marine cat". The marine otter spends much of its time out of the water and rarely ventures into freshwater or estuarine habitats, unlike the almost fully aquatic sea otter (Enhydra lutris) of the northeast Pacific and most other otter species.
Marine otters are found in littoral areas of southwestern South America, close to shore and in the intertidal areas of northern Peru (from the port of Chimbote), along the entire coast of Chile, and the extreme southern reaches of Argentina. Occasional vagrant sightings still occur as far afield as the Falkland Islands.
Marine otters are relatively small, and among otters, only the oriental small-clawed otter is smaller. Lengths range from 83 to 113 centimetres (33 to 44 in), not counting the tail of 30 to 36 centimetres (12 to 14 in). Weights can range from 3 to 5.8 kilograms (6.6 to 12.8 lb). Their fur is dark brown on the back and light brown on belly. The guard hairs cover short insulating fur with a grayish color. The fur is coarser and tougher than in sea otters.
The marine otter's lower jaws contain eight pairs of teeth, and the upper jaws eight or nine pairs. The teeth are developed for slicing rather than crushing.
Sexual dimorphism in this species not readily apparent.
Habitat and diet
The marine otter mainly inhabits rocky shorelines with abundant seaweed and kelp, and infrequently visits estuaries and freshwater rivers. It appears to select habitats with surprisingly high exposure to strong swells and winds, unlike many other otters, which prefer calmer waters. Caves and crevices in the rocky shorelines may provide them with the cover they need, and often a holt will have no land access at high tide. Marine otters avoid sandy beaches.
Behavior and reproduction
Marine otters are most often seen individually or in small groups of up to three. They are difficult to spot, swimming low in the water, exposing only their heads and backs. It is not known whether they are territorial, as males are occasionally seen fighting, yet fights have also been observed even between mating pairs. Fighting takes place on prominent rocks above the waterline, which are also used for resting, feeding, and grooming. Marine otters have also been observed feeding cooperatively on large fish, but it is not known how common the practice is.
The otters are diurnal, primarily active in the daytime.
Marine otters may be monogamous or polygamous, and breeding occurs in December or January. Litters of two to five pups are born in January, February or March after a gestation period of 60 to 70 days. The pups remain with their mother for about 10 months of parental care, and can sometimes be seen on the mother's belly as she swims on her back, a practice similar to that of the sea otter. Parents bring food to the pups and teach them to hunt.
Marine otters are rare and are protected under Peruvian, Chilean, and Argentine law. In the past, they were extensively hunted both for their fur and due to perceived competition with fisheries. Hunting extirpated them from most of Argentina and the Falkland Islands. Poaching is still a problem, but one of unknown magnitude. It is unknown how many marine otters exist in the wild or what habitats should be preserved to encourage their recovery. Marine otters were listed under CITES Appendix I in 1976, and are listed as endangered by the U.S. Department of the Interior.
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