The marine otter (''Lontra felina'') is a rare and relatively unknown

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

of the weasel family (

Mustelidae The Mustelidae (; from Latin , weasel) are a diverse family of carnivora, carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the s ...

). The

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

means "feline otter", and in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

, the marine otter is also often referred to as : "marine cat". The marine otter (while spending much of its time out of the water) only lives in saltwater, coastal environments and rarely ventures into

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

habitats. This saltwater exclusivity is unlike most other otter species, except for the almost fully

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

sea otter The sea otter (''Enhydra lutris'') is a marine mammal native to the coasts of the northern and eastern Pacific Ocean, North Pacific Ocean. Adult sea otters typically weigh between , making them the heaviest members of ...

(''Enhydra lutris'') of the North Pacific.

Description

The marine otter is one of the smallest otters and the smallest marine mammal, measuring from the nose to the tip of the tail and weighs . The tail measures . Its fur is coarse, with

guard hair Guard hair or overhair is the outer layer of hair of most mammals, which overlay the fur. Guard hairs are long and coarse and protect the rest of the pelage (fur) from abrasion and frequently from moisture. They are visible on the surface of the ...

s measuring up to in length covering dense, insulating

underfur A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...

. The marine otter is dark brown above and on the sides, and fawn on the throat and underside. The marine otter has

webbed ''Webbed'' is a 2021 puzzle-platform video game developed and published by Australian, Brisbane-based studio Sbug Games. A physics-based game set in a fantasy version of Queensland, players control a peacock spider whose goal is to rescue her ...

paw A paw is the soft foot-like part of a mammal, generally a quadruped, that has claws. Common characteristics The paw is characterised by thin, pigmented, keratinised, hairless epidermis covering subcutaneous collagenous and adipose tissue, whi ...

s and strong

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthro ...

s. The ventral side (underside) of the paws are partially covered in fur. It has 36

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

and a

dental formula Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...

of . The teeth are developed for slicing instead of crushing. The marine otter does not display

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

Distribution and habitat

Marine otters are found in

littoral The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...

areas of southwestern South America, close to shore and in the

intertidal The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

areas of northern

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

(from the port of

Chimbote Chimbote ; ) is a city in northwestern Peru. It is the largest city in the Ancash Region and the List of cities in Peru, tenth most populous in Peru. With a population of 425,367 in 2017, it is the capital of both Santa Province and Chimbote Dist ...

), along the entire coast of

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, and the extreme southern reaches of

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. Occasional vagrant sightings still occur as far afield as the

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and from Cape Dub ...

. The marine otter mainly inhabits rocky shorelines with abundant seaweed and

kelp Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a str ...

, 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 ecology

Rocky intertidal zones with natural crevices are ideal for marine otter dens and feeding areas. Because most of their time is spent hidden in caves, their behavior is difficult to observe. Marine otters actively avoid humans. In response to human activity, they will spend less time on coasts and stray from their dens during the day to fissures inaccessible to humans. Though generally avoidant of humans, their inhabitance of fishing villages is an indicator of the marine otter's ability to adapt to urbanization.

Reproduction

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 Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

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

. Parents bring food to the pups and teach them to hunt.

Feeding

Studies have shown latitudinal variations in diet, feeding periods, and dive time throughout the marine otter's distribution. Marine otters of southern Chile primarily feed on

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, while those in northern Chile mostly feed on

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

. The otters on Isla La Vieja,

presumably prey on a colony of Peruvian diving petrels regularly.Valqui, Juan (2012-03).
The marine otter Lontra felina (Molina, 1782): A review of its present status and implications for future conservation
. Mammalian Biology. 77 (2): 75–83. doi:10.1016/j.mambio.2011.08.004. ISSN 1616-5047. In January 2009, one was seen preying on magellanic flightless steamer duck chick in Puñihuil. The species shows

opportunistic 300px, ''Opportunity Seized, Opportunity Missed'', engraving by Theodoor Galle, 1605 Opportunism is the practice of taking advantage of circumstances — with little regard for principles or with what the consequences are for others. Opport ...

feeding behavior, sometimes eating small

s and even fruit of plants like '' Greigia sphacelata'' and '' Fascicularia bicolor.''

Taxonomy

The marine otter is of the Lutrinae, a subfamily of Mustelidae. Its exact

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

has been debated due to lack of data. A phylogenetic study by C. G. Van Zyll De Jong in 1987 proposed the following phenogram of the lutrinae, based on morphological data. Jong's proposed phenogram implied that the marine otter descended from the

Asian small-clawed otter The Asian small-clawed otter (''Aonyx cinereus''), also called oriental small-clawed otter and small-clawed otter, is an otter species native to South and Southeast Asia. It has short claws that do not extend beyond the pads of its webbed digits ...

, and its closest relative being the

North American river otter The North American river otter (''Lontra canadensis''), also known as the northern river otter and river otter, is a semiaquatic mammal that endemism, lives only on the North American continent throughout most of Canada, along the coasts of the U ...

. A 2004 study contradicted Jong's research. The following was proposed as a part of the taxonomy of the Mustelidae, based on cytochrome ''b'' sequences.

Threats

Human activity on coastlines poses disturbance to marine otters. Humans introduce domestic animals which may also disturb their dens. Humans, as well as domesticated species, may expose a marine otter population to disease. Marine otters may be entangled in fishing nets and die.

Microplastics Microplastics are "synthetic solid particles or polymeric matrices, with regular or irregular shape and with size ranging from 1 μm to 5 mm, of either primary or secondary manufacturing origin, which are insoluble in water." Microplastics a ...

have been found in the scat of marine otters. The effects of microplastics in marine mammals are still unclear.

Competition and predation

Gull Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

s and

South American sea lion The South American sea lion (''Otaria flavescens'', formerly ''Otaria byronia''), also called the southern sea lion and the Patagonian sea lion, is a sea lion found on the western and southeastern coasts of South America. It is the Monotypic ta ...

s may compete with marine otters for prey, the latter known to also attack the otters.

Orca The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopol ...

s and sharks allegedly prey on the otters, though direct attacks have not been observed.

Parasites

Marine otters are known to be susceptible to ''

Toxoplasma gondii ''Toxoplasma gondii'' () is a species of parasitic alveolate that causes toxoplasmosis. Found worldwide, ''T. gondii'' is capable of infecting virtually all warm-blooded animals, but members of the cat family (felidae) are the only known d ...

'' infection along the northern and central coast of

, though ''T. gondii''

seroprevalence Seroprevalence is the number of persons in a population who test positive for a specific disease based on serology (blood serum) specimens, often presented as a percent of the total specimens tested or as a proportion per 100,000 persons tested. As ...

in this otter species is lower than in other aquatic mustelids such as the

southern river otter The southern river otter (''Lontra provocax''), or South American river otter, is an otter species that lives in much of Patagonia. It is listed by the International Union for Conservation of Nature as an endangered species. Description A medium ...

and

American mink The American mink (''Neogale vison'') is a semiaquatic species of Mustelidae, mustelid native to North America, though human introduction has expanded its range to many parts of Europe, Asia, and South America. Because of range expansion, the Am ...

in southern Chile, likely because of the general dryness of the former environment.

Nematode The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...

s and acantocephalans are also known

endoparasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

of this species.

Conservation status

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

and the

. 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 CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

Appendix I in 1976, and are listed as endangered by the U.S. Department of the Interior.

References

External links

* *
International Otter Survival Fund
{{Taxonbar, from=Q644224

marine otter The marine otter (''Lontra felina'') is a rare and relatively unknown South American mammal of the weasel family (Mustelidae). The scientific name means "feline otter", and in Spanish, the marine otter is also often referred to as : "marine c ...

Marine mammals Mammals of Argentina Mammals of Chile Fauna of the Falkland Islands Carnivorans of South America Marine fauna of South America Western South American coastal fauna Endangered animals Endangered biota of South America Mammals described in 1782