Heaviside dolphins according to MammalMAP
Heaviside dolphins (Cephalorhynchus heavisidii) were originally named ‘haviside’ dolphins after Captain Haviside who brought a specimen of the cetacean from the coast of Namibia to the UK in the early 19th century. An accidental typo resulted in the cetacean being called a ‘heaviside dolphin’ and the name stuck!
Heaviside dolphins are small and robust. They are roughly the size of an average human. An adult Heaviside dolphin is approximately 1.7 meters in length and weighs an average of 60 – 70 kgs. They do not have beaks so they are often mistaken for porpoises.
Heaviside dolphins are often seen in small groups of 2 – 10 animals. They are shyer than their cetacean cousins but they do occasional bow ride nearby boats. They diet comprises of a variety of prey items found along their coastal habitat that stretches from along the coast of southern Angola to the southern tip of South Africa. Hake and kingklip make up to 50% of its diet. Octopods make up 25% and the remainder comprises of a mix of smaller fish.
There is no data available on the reproductive behaviour of Heaviside dolphins. There is also no data available on longevity. No wonder the IUCN Red list classifies Heaviside dolphins as a data deficient species. However, threats have been identified for this species. These animals are prone to entanglement in a variety of inshore fishing gear (e.g., beach seines, purse seines, trawls, and gillnets).
Cephalorhynchus heavisidii is found in coastal waters off of Africa’s Southwestern coast, from central Angola to the southern-most tip of South Africa. This species usually remain within 8 to 10 km of the shoreline, but has been sighted up to 45 nautical miles from the coast. While some studies suggest that Cephalorhynchus heavisidii does not migrate significant distances, and that there are resident dolphins in some areas, this is not well established. One study tracked a juvenile male that swam 158 km north of where he was tagged. Another juvenile male traveled 137 km north of his tagging site over a 17 month period, suggesting that average daily movements might be small. This species appears to have low population densities of around 5 individuals per 160 km.
Biogeographic Regions: ethiopian (Native )
- 2011. "Cephalorhynchus heavisidii (Gray, 1828)" (On-line). Encyclopedia of Life. Accessed March 14, 2011 at http://www.eol.org/pages/129532.
- 2010. "Cephalorhynchus heavisidii, Heaviside's Dolphin" (On-line). marinebio.org. Accessed March 14, 2011 at http://marinebio.org/species.asp?id=367.
- Culick, B. 2010. "Cephalorhynchus heavisidii" (On-line). Convention on Migratory Species. Accessed March 14, 2011 at http://www.cms.int/reports/small_cetaceans/data/c_heavisidii/c_heavisidii.htm.
The map shows where the species may occur based on oceanography. The species has not been recorded for all the states within the hypothetical range as shown on the map. States for which confirmed records of the species exist are included in the list of native range states.
- UNESCO-IOC Register of Marine Organisms
Adult Heaviside’s dolphins typically weigh between 60 and 70 kg, with an average body length of 1.74 m. Maximum girth is roughly 67% of the length of the body. Each individual has between 48 and 70 teeth. They are distinguished from other dolphins by their blunt head, robust body, triangular dorsal fin, and rounded paddle-like flippers. Heaviside's dolphins have a dark gray anterior surface with a dark blue-black patch beginning midway between the dorsal fin and the snout, and extending about halfway down the ventral surface of the body. White markings on their underside form a three-pronged fork, with another white rhomboidal patch on the chest and two smaller diamond-like patches just posterior to the flippers. They also have a dark blue-black stripe, which extends from the blowhole to the cape. Sexual dimorphism has not been reported in this species.
Range mass: 60 to 75 kg.
Average length: 1.74 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
- 2011. "Heaviside's Dolphin" (On-line). Accessed March 14, 2011 at http://www.angelfire.com/mb/dolphins/Heaviside.html.
Cephalorhynchus heavisidii is found exclusively in the Atlantic Ocean. Although it is most often found in waters less than 100 m deep, it has been sighted at depths up to 180 m. It is usually found in waters that are between 9 and 15ºC, but has been found in waters as warm as 19ºC. More than 87% of sightings occur in the Benguela Current.
Range depth: 180 (high) m.
Average depth: 100 m.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: pelagic ; coastal
Habitat and Ecology
The diet of Heaviside’s dolphin consists mainly of juvenile hake (individuals well below the modal length of commercially caught fish) (Sekiguchi et al., 1992). Other demersal fishes, pelagic schooling fishes, and cephalopods (including octopus) are also taken (Best and Abernethy 1994).
- UNESCO-IOC Register of Marine Organisms
The primary prey of Cephalorhynchus heavisidii includes hake and kingclip, which comprises nearly 49% of their diet. Octopods is also an important prey item for C. heavisidii, which makes up about 22% of their diet. The remainder of their diet generally consists of kingfish, gobies, and squid. Dolphins have fusiform, or torpedo shaped bodies, which allows them to swim at high speeds to avoid predation and catch prey.
Animal Foods: fish; mollusks
Primary Diet: carnivore (Piscivore )
- Fish, F., C. Hui. 1991. Dolphin swimming - a review. Mammal Review, 21/4: 181-195. Accessed March 14, 2011 at http://darwin.wcupa.edu/~biology/fish/pubs/pdf/1991MRDolphinswimming.pdf.
Cephalorhynchus heavisidii preys upon a number of different fish and cephalopods. Although this species is not a major prey item of any particular organism, body parts of dolphins have been found in the gut contents of killer whales and sharks. There is no information available regarding parasites of Cephalorhynchus heavisidii, nor has it been recorded to take part in any mutualistic or commensalistic relationships with other organisms.
- Ellis, E., A. Poor. 2006. "Order Cetacea" (On-line). Animal Diversity Web. Accessed March 14, 2011 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Cetacea.html.
- Wursig, B., M. Wursig. 2010. The dusky dolphin: master acrobat off different shores. United States of America: Academic Press. Accessed March 14, 2011 at http://books.google.com/books?id=KudBOfRXjWAC&pg=PA67&lpg=PA67&dq=dolphin+parasitic+relationship&source=bl&ots=uKBkne65bn&sig=-6asxrXN7a3cEv0_LSU5CQ36JhA&hl=en&ei=HJ59TdvyHcnprAGGv_jCBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q&f=false.
Though Cephalorhynchus heavisidii is not typically vulnerable to predation, humans pose a potential threat due to by-catch. In general, dolphins are subject to retaliatory killings by local fisherman and are sometimes slaughtered for their meat, which is considered a delicacy in Japan. However, the biggest threat to dolphins seems to be accidental killing. Drift fishing nets catch everything in their paths, including dolphins, and prevent them from reaching the surface for air. It has been estimated that drift fishing nets have killed more than 30 million dolphins worldwide since the 1960's.
- Humans (Homo sapiens)
- 2011. "Dolphin Predators" (On-line). Accessed March 14, 2011 at http://www.dolphins-world.com/Dolphin_Predators.html.
Life History and Behavior
Heaviside’s dolphins communicate visually, as dolphins have exceptional underwater vision. They also use tactile communication, swimming near other individuals and rubbing against one another to build affiliative relationships. Acoustically, they are able to communicate through a series of whistles and clicks ranging between 1.5 and 11.0 KHz. They communicate chemically by releasing pheromones from pores in their anal glands. Heaviside’s dolphins also rely heavily on echolocation to perceive their surroundings.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; acoustic ; echolocation ; chemical
- 2006. "What is the Dolphin's Lifespan?" (On-line). The Dolphin Place. Accessed March 14, 2011 at http://thedolphinplace.com/QandA.html#6.
- Mann, J. 1999. Cetacean societies: field studies of dolphins and whales. Chicago: University of Chicago Press. Accessed March 14, 2011 at http://books.google.com/books?id=W-UQNoxMONwC&pg=PA275&lpg=PA275&dq=dolphin+pheromones&source=bl&ots=WRkSPStisj&sig=BVz6IpZNP1Is-LwkJckI1FD9jQE&hl=en&ei=XXJ9TYnVFMWArQH9npD9Dw&sa=X&oi=book_result&ct=result&resnum=5&ved=0CDYQ6AEwBA#v=onepage&q=dolphin%20pheromones&f=false.
There is no information available regarding the average lifespan of Cephalorhynchus heavisidii in captivity or in the wild. The average lifespan of most wild delphinids ranges from 17 to 25 years, with a few living into their early 50s. Although similar averages are found for captive dolphins, few captive individuals live past their 20s. In general, delphinids are vulnerable to bacterial, fungal, and viral infections and have been found to suffer from heart and respiratory disease, stomach ulcers, and even cancer. Dolphins are also vulnerable to a number of different parasites including flukes, tapeworms, and roundworm.
- 2006. "Heaviside Dolphin" (On-line). Dolphins Resource Center. Accessed March 14, 2011 at http://www.tagate.com/dolphins_resource_center/different_species_of_dolphins/heaviside_dolphin.shtml.
- Moore, S. 2011. "What is a Dolphin's Lifespan?" (On-line). Accessed March 14, 2011 at http://www.ehow.com/about_4586901_what-dolphins-life-span.html.
There is no information available regarding the mating system of Heaviside's dolphins. However, bottlenose dolphins, spinner dolphins, and common dolphins are promiscuous.
Heaviside's dolphins breed once every 2 to 4 years from spring to late summer. Gestation lasts for 10 to 11 months. Females usually give birth to only one offspring at a time, as there is limited space for in utero development. To account for the limited space in the uterus, during development, the tail flukes and dorsal fins of fetuses are cartilaginous and fold over. Newborns average 85 cm in length. Birth mass has not been recorded for this species. However, newborn bottlenose dolphins range from 11.3 to 18.1 kg, and Irrawaddy dolphins, which average 96 cm in length at birth, has an average birth mass of 12.3 kg. There is no information available regarding weaning and time to independence for this species. Bottlenose dolphins begin weaning as early as 32 months and are fully weaned by 48 months, while time to independence ranges between 3 and 6 years. Female Heaviside's dolphins reach sexual maturity between 5 and 9 years of age, and males reach sexual maturity between 6 and 9 years of age.
Breeding interval: Haviside's dolphins breed every 2 to 4 years.
Breeding season: Haviside's dolphins breed from spring to late summer.
Range gestation period: 10 to 11 months.
Range age at sexual or reproductive maturity (female): 5 to 9 years.
Range age at sexual or reproductive maturity (male): 6 to 9 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Cephalorhynchus heavisidii calves swim in echelon position, that is, in close proximity to the mid-lateral flank near the dorsal fin of the mother. This allows the calf extra speed at a lower tailbeat frequency, because it is able to ride along the pressure wave that its mother’s body creates. However, it has been shown that this causes extra strain on the mother, who is able to swim at only 76% of her mean maximum speed when swimming by her self. Most dolphin calves develop strong social bonds with their mother, which remains even at 3 years of age. This extended mother-young association is thought to be due largely to the still-improving physical performance and social skills of calves. There is no information available regarding paternal investment in calf development.
Parental Investment: precocial ; female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); extended period of juvenile learning
- 2011. "Cephalorhynchus heavisidii (Gray, 1828)" (On-line). Encyclopedia of Life. Accessed March 14, 2011 at http://www.eol.org/pages/129532.
- 2007. "Maternity" (On-line). Dolphin Research Center. Accessed March 14, 2011 at http://www.dolphins.org/marineed_maternity.php.
- Gubbins, C. 2002. Use of home ranges by resident bottlenose dolphins (Tursiops truncatus) in a South Carolina estuary. Journal of Mammalogy, 83/1: 178-187. Accessed March 14, 2011 at http://www.asmjournals.org/doi/full/10.1644/1545-1542(2002)083%3C0178%3AUOHRBR%3E2.0.CO%3B2.
- Koss, M., L. Mahan, S. Merrill. 2011. "Orcaella brevirostris" (On-line). Animal Diversity Web. Accessed March 14, 2011 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Orcaella_brevirostris.html.
- Mann, J., R. Connor, L. Barre, M. Heithaus. 2000. Female reproductive success in bottlenose dolphins (Tursiops sp.): life history, habitat, provisioning, and group-size effects. Behavioral Ecology, 11/2: 210-219. Accessed March 14, 2011 at http://beheco.oxfordjournals.org/content/11/2/210.abstract.
- Murphy, S., A. Collet, E. Rogan. 2005. Mating strategy in the male common dolphin (Delphinus delphis): what gonadal analysis tells us. Mammal Review, 86/6: 1247-1258. Accessed March 14, 2011 at http://www.asmjournals.org/doi/pdf/10.1644/1545-1542(2005)86%5B1247%3AMSITMC%5D2.0.CO%3B2.
- Noren, S. 2007. Infant carrying behaviour in dolphins: costly parental care in an aquatic environment. Functional Ecology, 22/2: 284-288. Accessed March 14, 2011 at http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2435.2007.01354.x/full.
- Noren, S., V. Cuccurullo, T. Williams. 2004. The development of diving bradycardia in bottlenose dolphins ( Tursiops truncates). Journal of Comparative Physiology, 174/2: 139-147. Accessed March 14, 2011 at http://www.springerlink.com/content/mj1w6nvreaclbar3/.
- Noren, S., E. Edwards. 2006. Female reproductive success in bottlenose dolphins (Tursiops sp.): life history, habitat, provisioning, and group-size effects. Marine Mammal Science, 23/1: 15-29. Accessed March 14, 2011 at http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2006.00083.x/full.
- Perrin, W., S. Mesnick. 2003. Sexual ecology of the spinner dolphin, Stenella longirostris: geographic variation in mating system. Marine Mammal Science, 19/3: 462-483. Accessed March 14, 2011 at http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2003.tb01315.x/abstract.
Molecular Biology and Genetics
Barcode data: Cephalorhynchus heavisidii
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
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Download FASTA File
Statistics of barcoding coverage: Cephalorhynchus heavisidii
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
Cephalorhynchus heavisidii is listed as “data deficient” on the IUCN Red List of Threatened Species. CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) lists Cephalorhynchus heavisidii under Appendix II, meaning that though this species is not necessarily threatened with extinction, its trade must be regulated so that its survival is not jeopardized. Cephalorhynchus heavisidii is vulnerable to harpoons and guns used by humans hunting close to shore, where about 100 are killed annually. Also, entanglement in fishing gear poses a significant threat. In 1983, 67 were caught in nets off Namibia, and 57 off of South Africa. Although overfishing of their primary prey may pose a threat to their survival, little evidence exists to support this claim. As an inshore species, C. heavisidii is susceptible to pollution and boat traffic, and low levels of DDT have been found in some individuals. This species is currently protected from commercial hunting and fishing throughout its geographic range. It is also protected by a 322 km Exclusive Fishery Zone (EFZ) off the coast of South Africa and a 20 km EFZ off the coast of Namibia.
CITES: appendix ii
IUCN Red List of Threatened Species: data deficient
- Reeves, R., E. Crespo, S. Dans, T. Jefferson, L. Karczmarski, K. Laidre, G. O'Corry-Crowe, S. Pedraza, L. Rojas-Braho, E. Secchi, E. Slooten, B. Smith, J. Wang, K. Zhou. 2008. "Cephalorhynchus heavisidii" (On-line). IUCN Red List. Accessed March 14, 2011 at http://www.iucnredlist.org/apps/redlist/details/4161/0.
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Data Deficient
- 1994Insufficiently Known(Groombridge 1994)
- 1990Insufficiently Known(IUCN 1990)
- 1988Insufficiently Known(IUCN Conservation Monitoring Centre 1988)
Concern has been expressed about the potential effects of pollution and boat traffic (Culik 2004). However, organochlorine levels in a small sample of Heaviside’s dolphins failed to indicate significant exposure to DDT in the coastal waters of South Africa’s west coast, where the scarcity of arable land and low rainfall may help minimize pesticide residue inputs to the marine environment (De Kock et al. 1994). Also, low human population densities and the scarcity of large ports along most of the species’ range probably help reduce the possibility of adverse effects from boat traffic (Best pers. comm.).
More information is needed on the distribution of the species in Angolan waters in particular, as well as on the nature and extent of directed and incidental catches. More research emphasis should in future also be placed on possible detrimental interactions due to the overfishing of prey stocks, especially hake. Increased inshore fishing pressure will inevitably increase interactions between the fisheries and Heaviside’s dolphins (Peddemors 1999).
Relevance to Humans and Ecosystems
There are no known adverse effects of Cephalorhynchus heavisidii on humans. Although local fisherman may contend that this species decreases local fish abundance, there is no documented evidence to support this.
Cephalorhynchus heavisidii provides no known economic benefits to humans.
IUCN Red List Category
- IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
Haviside's dolphin (Cephalorhynchus heavisidii), or alternatively Heaviside's dolphin, is a small dolphin found off the coast of Namibia and the west coast of South Africa. It is one of four dolphins in the genus Cephalorhynchus — the others being the Chilean dolphin, Hector's dolphin, and Commerson's dolphin.
Haviside's dolphin, whose binomial name references heavisidii, is actually named after a Captain "Haviside", who brought a specimen from Namibia to the United Kingdom early in the 19th century. However, its name was once misspelled Heaviside, after a prominent surgeon, Captain Heaviside who collected cetacean and other animal species. The latter name stuck and is the most common in the literature. Some authorities, including the Encyclopedia of Marine Mammals and Mammal Species of the World use the originally intended name of Haviside's dolphin.
Population and distribution
Although sightings of the species are not uncommon off the Skeleton Coast of Namibia, Haviside's dolphins have not been systematically studied by scientists. They have been recorded off the coast of northern Namibia at 17°S and as far south as the southern tip of South Africa. Sightings are often recorded from major population centres such as Cape Town and towns such as Walvis Bay. Sightings are likely from Lambert's Bay either from the shore or from boat trips run from the harbour. No estimates of abundance exist.
Haviside's dolphin is a fairly small dolphin, growing to about 1.8 m (5 ft 11 in) in length and weighing up to 75 kg. Their size and the bluntness of their heads lead these dolphins to often be mistaken for porpoises. The head is coloured a dark grey. The front half of the upper side and the flanks are a much lighter grey. The dorsal fin, fluke and back half of the back are again a darker grey colour. The underbelly is white, with flashes of white on the flanks below the dorsal fin.
Males reach sexual maturity at about seven to 9 years. Females reach breeding age at the same time. The gestation period is probably 10 months. Mating occurs in spring and summer. Females are believed to calve on average once every three years. The maximum known age of a Haviside's dolphin is 20 years. This relatively short lifespan, coupled with the long calving period, causes a naturally low population growth rate. Therefore, the species is particularly sensitive to being hunted.
Haviside's dolphins are active and social animals. They typically congregate in groups of about five to 10 in number, but sometimes in larger groups. They are able to swim fast. Part of their play and social activity is to jump vertically clear of the water, turn in the air, and fall back into the sea with virtually no splashing or noise.
Heaviside's dolphin is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
Heaviside's dolphin is covered by the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia.
- Reeves, R.R., Crespo, E.A., Dans, Jefferson, T.A., Karczmarski, L., Laidre, K., O'Corry-Crowe, G., Pedraza, S., Rojas-Bracho, L., Secchi, E.R., Slooten, E., Smith, B.D., Wang, JY. & Zhou, K. (2008). "Cephalorhynchus heavisidii". IUCN Red List of Threatened Species. Version 2012.2. International Union for Conservation of Nature. Retrieved 18 January 2013.
- Encyclopedia of Earth. 2011. Cephalorhynchus heavisidii. Eds. C.Michael Hogan and C.J.Cleveland. Encyclopedia of Life (contributor) Washington DC
- "Appendix II" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5th March 2009.
- Convention on Migratory Species page on the Heaviside's dolphin
- Western African Aquatic Mammals MoU, Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia
- National Audubon Society: Guide to Marine Mammals of the World Reeves, Stewart, Clapham and Powell (2002)
- Cephalorhynchus dolphins, Encyclopedia of Marine Mammals, pp. 200–202, Stephen M. Dawson (1998) ISBN 0-12-551340-2