Lagenorhynchus acutus, Atlantic White-sided Dolphin [+]

Kingdom Animalia Phylum Chordata Class Mammalia Order Cetacea Family Delphinidae Genus Lagenorhynchus species: Lagenorhynchus acutus [+ITIS +WoRMS]

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Description & Behavior

The Atlantic white-sided dolphin, Lagenorhynchus acutus (Gray, 1828), gets its name from the Greek lagenos, which means bottle, rhynchus, which means snout or nose, and acutus from the Latin, which means sharp or pointed and refers to the sharply pointed dorsal fin. This dolphin ranges from 2.5-3 m in length. The pectoral fin is about 30 cm in length and the dorsal fin may be up to 50 cm in height. The tail flukes range from 30-60 cm across. Females may be considerably smaller than males and average only 182 kg.

The dorsal region of L. acutus is black and its flanks are gray. The ventral surface is white. This dolphin's distinguishing characteristic is the yellow-white patches on the dorsal side and black rings around the eyes. L. acutus has a stocky body with sickle shaped fins. The beak is prominent with 30-40 pairs of pointed teeth.

Male longevity is about 22 years, female longevity is about 27 years.

World Range & Habitat

The Atlantic white-sided dolphin, Lagenorhynchus acutus, is found in the temperate and subarctic waters of the north Atlantic Ocean from southern Greenland to Massachusetts, and from the British Isles to western Norway. Some have been spotted as far south as the Barents Sea, Baltic Sea, Azores, and the Adriatic Sea.

The Atlantic white-sided dolphin inhabits open water 40-270 m in depth around the continental shelf and is rarely seen from shore. This species is typically found in waters with low-salinity and surface temperatures between 6-20°C.

They migrate seasonally along the continental slope.

» GBIF occurrence data in Google Earth [Tips] | Ocean Biogeographic Information System (OBIS) (World Distribution) [about]

Feeding Behavior (Ecology)

The Atlantic white-sided dolphin, Lagenorhynchus acutus, feeds on shrimp, smelt, hake, squid and herring. Its major predators are orca (killer whales) and sharks.

Life History

Male Atlantic white-sided dolphins, Lagenorhynchus acutus, sexually mature between 2.1-2.4 m in length, females between 1.94-2.22 m or about 6-12 years of age. Calves are usually born in June and July following a gestation period of about 10 months long measuring 1.1-1.2 m in length and averaging about 25 kg. Females nurse for about 18 months and give birth every 2-3 years.

Conservation Status/Additional Comments

Exact data on the population size of Lagenorhynchus acutus is unavailable but the species is thought to be abundant. Its primary threats in addition to predation are ocean pollution and entanglement in fishing gear.