Lissodelphis peronii
southern right whale dolphin

Lissodelphis peronii, the southern right whale dolphin, has a circumpolar distribution. It is found only in cool, temperate subtropical to subantarctic waters of the Southern Hemisphere. The southern limit of this species' distribution is generally bounded by the Antarctic Convergence. The northward counterclockwise flowing Humboldt and Benguela current systems may allow this coldwater species to extend its range northward along the west coast of the Southern Hemisphere continents. The northernmost record is at 12 degrees S. in northern Peru. This is an open ocean species coming close to shore only in deep water coastal areas. (Jefferson et al., 1993; Jefferson et al., 1994)

Southern right whale dolphins reside most often in cool, deep, offshore waters of the Southern Hemisphere with temperatures of 1-20 degrees celsius. They are sometimes observed nearshore, especially where deep water approaches the coast. (Jefferson et al., 1994)

The southern right whale dolphin is mostly black dorsally and white ventrally. The border between the two colors meet on the posterior flank, and it dips to where the flipper inserts, then sweeps upward and across the melon before the blowhole. The beak, anterior melon, and flippers are white. A black band is seen on the trailing edge of the flippers as well. Gray coloration is sometimes seen on the dorsal surface of the flukes as opposed to black. Several different color variants have been reported in this species including: those with white spots on the head, or variations in the amount of black and white on the body and fins. Calves have been reported to possess a muted color pattern of brown or gray instead of balck and white.

The name '/Lissodelphis/' refers to the fact that both species of right whale dolphin (northern and southern) are characterized by complete absence of a dorsal fin or dorsal ridge. Southern right whale dolphins along with their northern counterpart are the most slender of all cetaceans. They have a dorso ventrally compressed body, a straight mouthline, a moderately well demarcated, but short, beak, small recurved flippers with pointed tips about 1/4 of the way back from the snout tip, and small concave flukes with a deep to medium notch. Southern right whale dolphins have reached a reported 2.97 m in length, and males tend to grow larger than females.

The skull is slender and light with a rostrum that is elongated and tapers to a sharp point. The rostral length is roughly twice the width. The premaxilla are widely separated through to the rostrum tip and the pterygoid bones are also separated. Teeth are small, slender and sharp, ranging in number from 37-54. In general, there are slightly more teeth in the lower jaw. (Jefferson et al., 1994; Jefferson et al., 1993; Macdonald et al., 1984; Nowak, 1991)

Social organization: southern right whale dolphins are highly gregarious. They are seen singly, but most often are in groups of up to 1000. Mean herd size was determined off of Chile and was found to be 210 individuals. Herd configurations vary, they may be tightly packed groups, herds with prominent subgroups, v-formations, or "chorus lines."

Social interaction: Southern right whale dolphins along with their northern counterpart are most often found in association with dolphins of the genus Lagenorhynchus, and with pilot whales, genus Globicephala.

Swimming and diving: Slow swimming behavior typically involves exposure of the head and blowhole only to respire. Fast moving herds may swim just below the surface, rapidly surface to breathe, then resubmerge. While in fast swimming mode, herds may also swim rapidly at the surface where they perform low angle leaps, belly flops, fluke slaps, side slaps, and they occasionally bowride. Speeds from 22-45 km per hr. and a diving period of 10-75 sec. have been reported for southern right whale dolphins, but entire herds may dive for 6.5 min.

Sound production: Although northern right whale dolphins have been described to produce clicks, the sounds of southern right whale dolphins have not been reported. (Jefferson et al., 1994; Jefferson et al., 1993)

Southern right whale dolphins prey primarily on mesopelagic fishes, especially lanternfish, (family Myctophidae) and cephalopods such as squid. They may dive to depths in excess of 200 m in search of food. Entire schools have been observed to dive for as long as 6 minutes and 30 seconds. (Jefferson et al., 1994; Nowak, 1991)

None.

Southern right whale dolphins are reportedly infrequently caught off the coasts of Peru and Chile, where they are used as food or crab bait. (Jefferson et al., 1994)

They were occasionally taken for food by whalers in the 1800's, although now they appear to be nowhere heavily hunted. (Jefferson et al., 1993)

Preliminary boat surveys suggest that the southern right whale dolphin may be one of the most common cetaceans in northern Chilean coastal waters. Increasing numbers of southern right whale dolphins have stranded on beaches of north-central Chile in the last few years, some have been returned to sea alive, but it is not known if they survived.

It is not confirmed, but likely that killer whales and possibly large sharks are predators for the southern right whale dolphin. (Jefferson et al., 1994; Jefferson et al., 1993; Joint Nature Conservation Committee, 1993)

Parasites such as the trematode fluke can cause major damage to the air sinuses, inner ears, and brain, and has been designated as a factor in the stranding and death of some animals. (Jefferson et al., 1994)

Southern right whale dolphins were recorded traveling at speeds as great as 45 km per hr., and a boat traveling 33 km per hr. was easily outdistanced in a 10 minute chase. (Nowak, 1991)