Mesoplodon europaeusGervais's beaked whale

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Geographic Range

Mesoplodon europaeus is known only from strandings, so the known distribution may be affected by ocean currents and efforts in North America to retrieve stranded animals. Recorded from as far north as New York and as far south as Trinidad, Mesoplodon europaeus is probably the most abundant member of its genus in the Gulf of Mexico. Records from the eastern side of the Atlantic are more spotty, ranging from Ireland to Guinea Bissau in Africa. A relationship has been suggested between water temperature and prey species distribution, thus affecting the distribution of different Mesoplodon species.

(McLeod, 2000a; Robineau and Vely, 1993)

Habitat

Mesoplodon europaeus lives in warm to tropical pelagic waters.

(Cetacea, 2001; Debrot and Barros, 1992)

Physical Description

The coloration of Mesoplodon europaeus is black or dark grey on the back fading to a lighter gray on the sides and belly. For a cetacean, the head is small with respect to total body size. The tails of ziphiids (beaked whales) are unusual among cetaceans in having no notch in the center of the fluke. Some stranded specimens, particularly adult males, have many scars on their bodies, presumably from sharks and fighting between males.

Nearly all ziphiids have a greatly reduced number of teeth, and Mesoplodon europaeus has only two in the lower jaw. These two teeth are are visible outside the mouth as small “tusks” near the front of the rostrum. Conchoderma, stalked barnacles, often attach themselves to these teeth. Tusk shape varies between species and it has been proposed that these difference evolved in order to aid the animals in differentiating their own species, as Mesoplodon species are otherwise very similar in appearance. It is extremely difficult to distinguish the similar-looking species of this genus by sightings, and sometimes even when using the diagnostic characters of the skull.

(Lynn and Ross, 1992; Martin et al, 1990; McLeod, 2000b; Robineau and Vely, 1993; Vaughn et al, 2000; Pitman, 2001)

  • Range mass
    1200 + (high) kg
    lb
  • Range length
    4 to 5.2 m
    13.12 to 17.06 ft

Reproduction

Very little information is available, but females are thought to be sexually mature by the time they reach 4.5 m size.

(Martin et al, 1990; Poss, 1998; Pitman, 2001)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • viviparous

As with all cetaceans, the young are necessarily precocial at birth and Mesoplodon europaeus are about 2.1 m long at birth.

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Gervais' beaked whale is known to live to at least 27 years old in the wild.

(Pitman, 2001)

  • Range lifespan
    Status: wild
    27 (high) years
  • Average lifespan
    Status: captivity
    48 years
    AnAge

Behavior

This species tend to live in small groups or as couples. From scarring on stranded specimens, it is assumed that interspecific fighting occurs at least among adult males.

(The Azorean Whale Watching Base, 2000; Debrot and Barros, 1992)

Communication and Perception

Food Habits

From stomach contents of stranded M. europaeus it is known that they eat primarily squid (Octopoteuthis spp., Mastigoteuthis spp. and Taonius spp.), deep sea shrimp(Neognathophausia ingens) and mesopelagic viper fish (Chauliodus sloani and Nesiarchus nasutus). The stomach is divided into multiple chambers. The purpose of this is undetermined, as squid and fish are easily digested, as opposed to the tough material eaten by most animals with such stomach morphology.

(Vaughn et al, 2000; Debrot and Barros, 1992; Martin et al, 1990)

  • Animal Foods
  • fish
  • mollusks
  • aquatic crustaceans

Predation

From distinctive scars on some stranded beaked whale specimens it is known that cookie-cutter sharks do attack M. europaeus. The whale probably uses its tusks to protect itself from this and other predators, as well as for interspecific fighting.

(Pitman, 2001)

Conservation Status

Contributors

Tawny Seaton (author), University of Michigan-Ann Arbor, Bret Weinstein (editor), University of Michigan-Ann Arbor.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

piscivore

an animal that mainly eats fish

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born

References

2001. "Australian Museum Online: Viper Fish, *Chauliodus sloani* Bloch & Schneider, 1801" (On-line). Accessed Sept 17, 2001 at http://www.amonline.net.au/fishes/fishfacts/fish/csloani.htm.

2001. "Cetacea: *Mesoplodon europaeus* (Gervais' Beaked Whale)" (On-line). Accessed Sept 17, 2001 at http://www.cetacea.org/gervais.htm.

2000. "The Azorean Whale Watching Base technical file: *Mesoplodon europaeus* - Gervais beaked whale" (On-line). Accessed Sept 22, 2001 at http://www.espacotalassa.com/gb/16_species/docs/m_europaeus.htm.

Debrot, A., N. Barros. 1992. Notes on a Gervais' beaked whale *Mesoplodon europaeus*, and a dwarf sperm whale, *Kogia simus*, stranded in Curacao, Netherlands Antilles. Marine Mammal Science, 8, No. 2: 172-178.

Lynn, S., D. Reiss. 1992. Pulse sequence and whistle production by two captive beaked whales, *Mesoplodon* species. Marine Mammal Science, 8, No. 3: 299-305.

Martin, V., R. Vonk, S. Escorza, R. Montero. 1990. Records of Gervais' beaked whale *Mesoplodon europaeus* on the Canary Islands. Proceedings of the Fourth Annual Conference of the European Cetacean Society, 2-4 March 1990: 95.

McLeod, C. 2000a. Review of the distribution of *Mesoplodon* species (Order Cetacea, family Ziphiidae) in the North Atlantic. Mammal Review, 30, No. 1: 1-8.

McLeod, C. 2000b. Species recognition as a possible function for variations in position and shape of the sexually dimorphic tusks of *Mesoplodon* whales. Evolution, 54, No. 6: 2171-2173.

Pitman, R. 2001. "Mesoplodont whales". Pp. 738-742 in W Perrin, B Wursig, J Thewissen, eds. "Encyclopedia of Marine Mammals". San Diego: Academic Press.

Poss, S. 1998. "Species at risk in the Gulf of Mexico ecosystem." (On-line). Accessed Sept 22, 2001 at http://lionfish.ims.usm.edu/~musweb/endanger.html.

Robineau, D., M. Vely. 1993. Stranding of a specimen of Gervais' beaked whale (*Mesoplodon europaeus*) on the coast of West Africa (Mauritania). Marine Mammal Science, 9, No. 4: 438-440.

Vaughn, T., J. Ryan, N. Czaplewski. 2000. Mammalogy. Orlando: Sunders College Publishing.