There are many other common names for this species beside the common name Peales dolphin. These are Peales Porpoise, black-chinned dolphin, and Southern white-sided dolphin. In Spanish it used to be called llampa or tunina in Chile. Now it is called delfin austral (southern dolphin) in Chile and Argentina.
(Goodall et al, 1997)
Sounds emitted under water by L. australis include low frequency clicking noises and a "rapid tonal sound", but no whistling. There is little research on vocalizations, as they seem to be very timid communicators around boats taking the data.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Lagenorynchus australis has not been studied intensively to determine population trends. There are a few human sources of mortality that may be of a concern in the future. These include shore-set gill nets (accidental catch), inshore fishing (incidental catch), and salmon farms near Chile (a few have been caught in the anti-pinniped nets despite the loud sounds made underwater to deter them). Deep sea fishermen have been known to occasionally catch a few Peales dophins in their mid-water nets. A more serious situation is occurring near crab fisheries where the use of nets has been outlawed. Fisheries have been known to use harpooned L. australis as bait. (Nowark, 1999 and Goodall et al, 1997)
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: data deficient
Very little has been recorded about the developmental cycle in L. australis. The only studies recorded represent measurements of the ovaries of a few female L. australis. These measurements were representative of the different sexual maturities and the data showed the older females as having more ovarian scars. Even less information has been gathered about males and their sperm activity. There was not enough conclusive information to make any statements. No information has been collected about the young in L. australis and there have been no specimens collected or found with a fetus inside. Because of this we are left to assume that this species is similar in the developmental patterns of better-known dolphin species.
(Goodall et al, 1997 and Claver et al, 1992)
It is difficult to speculate on how these acquatic mammals might negatively impact humans. There are no reports of negative interactions, but it is possible that through their predatory behavior, populations of Peale's dolphins could negatively impact commercial or subsistence fisheries. However, this is just speculation, and there are no reports of this being the case.
Humans have occasionally harpoon Peales dolphins for use as bait.
There is so little known about Peales dolphins that their effect on the pelagic ecosystem is unknown. However, because they prey upon a number of types of animals, there is a potential impact of these dolphins upon prey populations.
Species Used as Host:
Peale's dolphins may feed in groups or alone. It has been hypothesized that this species may tend to feed alone when food is scarce and in groups when food is of abundance. When in groups, L. australis usually exhibits what is called "flower" or "starburst" feeding. They encircle their prey until they form a large group and then they feast. This is mostly done within the kelp beds. When they are sighted eating alone it is usually close to shore. When diving for prey it has been reported that they stay under water from between 10.36 seconds to 1.46 minutes.
Not very many L. australis have been dissected for examining the stomach contents, but known prey species are very extensive all the same.
Foods eaten include: Pleoticus muelleri (Argentine shrimp), squid (Loligo gahi and Illex argentinus), Kingklip fish (Genypterus blacodes), Argentine hake (Merluccius hubbsi), southern cod (Salilota australis), hagfish (Myxine australis), Pantagonian grenadier (Marcuronus magellanicus), red octopus (Enteroctopus megalocyathus), other species of herring, makarel, capelin, anchovies, crustaceans and whelks (gastropods).
Animal Foods: fish; mollusks; aquatic or marine worms; aquatic crustaceans
Primary Diet: carnivore (Piscivore , Molluscivore )
Lagenorynchus australis lives mostly in the mildly cold and temperate waters off of South America and the Falkland Islands in the South Atlantic Ocean. One sighting has been reported near the Cook Islands also.
Biogeographic Regions: neotropical (Native ); atlantic ocean (Native )
L. australis is usually found near the coast. These dolphins love to swim in and around the channels within kelp beds. They have also been sighted around sandbars and shallow bays. Most sightings of L. australis occur while there are strong tidal currents and during medium tides.
Peale's dolphins tend to inhabit two types of coastline. In the south they are usually found near channels and fjords. In the northern and eastern coast ranges, where the continental shelf underwater is very wide, they tend to be found in the open coast. In the open coast they have been found to swim as deep as 300 meters. There is little kelp there, but more southward and towards the Falkland Islands there are many kelp beds and this is where you will mostly find L. australis.
Range depth: 300 (high) m.
Habitat Regions: temperate ; saltwater or marine
Aquatic Biomes: coastal
Scientists are able to determine the age of Peale's dolphins by looking at their teeth but no records or studies explain how this is accomplished. The oldest recorded specimen of L. australis was thirteen years old.
Range lifespan
Status: wild: 13 (high) years.
L. australis has many distinguishing physical characteristics. Some of these include a torpedo shaped body, a dark gray back, a white belly, a light gray area on flanks that extends from behind to the anus and a skinny white band that begins behind the dorsal fin and gets wider as it extends backwards. This latter feature is termed the “tail stock”.
L. australis has double black rings around both eyes and that extend forward to the nose. A final distinguishing feature that separates this species from other similar looking species is a circular patch of varying gray colors that is right on the thoracic area of the back.
The young of L. australis tend to look the same as the adults, but are much lighter in color. They become darker as they mature.
The teeth of L. australis seem to be variable. The maximum number on each upper jaw is thirty-seven and thirty-six on each lower jaw. Many teeth are hidden in the gums of the mouth.
The pectoral fin length is approximately 30 cm, and the dorsal fin can be up to 50 cm in height. The tail fluke is generally 30-60 cm wide, and the beak is up to 5 cm in length.
These animals may weigh up to 115 kg.
Average mass: 115 kg.
Range length: 150 to 310 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
There are no known predators of L. australis.
Little is known bout the mating system of these animals.
In general it has been noted that species within the genus Lagenorynchus have gestation periods of ten to twelve months. Calving season for L. australis usually occurs between the southern spring and autumn but a calf can be born as early as October. Females tend to have only one calf per birth (maybe two) and they also move more inshore to do this. Some records show that when two of these dolphins were spotted together in the past, they were only considered a mother and calf if the smaller of the two animals was one third or less the size of the adult accompanying it. On visual sightings alone, this is probably still the most common way to tell a calf from an adult.
Although data are not available for this species, in another member of the genus, L. acutus, young are between 90 and 125 cm at birth. They nurse for about 18 months, and become independent of their mothers around the age of 2 years. It is not known whne these animals mature sexually.
Breeding season: It is not known for certain when mating occurs, but births occur during the Southern Spring to Autumn.
Range number of offspring: 1 to 2.
Average number of offspring: 1.
Range gestation period: 10 to 12 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Young are precocial and swim along side of their mothers from birth. The mother provides her calf with milk for approximately 18 months, although the calf may remain dependent upon her for an additional 6 months. It is not known what role males play, if any, in the parental care of this species.
Parental Investment: precocial ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence; extended period of juvenile learning
