Galapagos Tortoise, Chelonoidis nigra
May 2010

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Galapagos tortoise

(Auffenberg 1974) (Caccone et al. 1999) (Caccone et al. 2002) (Chiari et al 2009)
(Ernst & Barbour 1989) (Fritz & Havas 2007) (IUCN 2010) (King & Burke 1989) (Le et al. 2006) (Poulakakis et al. 2008) (Pritchard 1996, 1997) (Reptiles Database 2010) (Russello et al 2005) (Russello et al. 2007) (Russello et al. 2010)
(Van Denburgh 1914) (Welch 1994) (Zug 1997)

Describer (Date): Quoy and Gaimard, 1824 (Testudo nigra); Harlan, 1827 (Chelonoidis nigra)

    Phylum: Chordata
        Class: Reptilia
             Order: Testudines
                Suborder: Cryptodira
                    Family: Testudinidae (Terrestrial turtles with high domed carapace, elephantine feet)
                           Genus: Chelonoidis
                                  Species: Chelonoidis nigra
                                        Subspecies: (According to Tortoise and Freshwater Turtle Specialist Group 1996)
 C. n. abingdoni  -Pinta (Abingdon) Island (extinct in the wild, 1 captive)
   C. n. becki -Volcan Wolf and vicinity, north Isabela (Albemarle) Island
   C. n. chathamensis  -San Cristobal (Chatham) Island (extinct since 1933)
 C. n. darwini -San Salvador (James or Santiago) Island
   C. n. duncanensis   - Pinzón (Duncan) Island
   C. n. guntheri -Sierra Negra area of SE Isabela (Albemarle) Is.
C. n. hoodensis  -Espanola (Hood) Island
C. n. microphyes -Volcan Darwin and vicinity, N central Isabela Is.
C. n. nigra  -Southwest Isabela (Albemarle) Island (extinct)
C. n. porteri  -Santa Cruz (Indefatigable) Island
C. n. phantastica -Fernandina (Narborough) Island (probably extinct, see below)
C. n. vandenburghi  -Volcan Alcedo and vicinity, central Isabela Is.
C. n. vicina -Cerro Azul and vicinity, southern Isabela Is.

Taxonomy Common Names Phylogeny and Biogeography (Auffenberg 1974) (Caccone et al. 1999) (Caccone et al. 2002) (Crawford et al. 2012) (Le et al. 2006)
(DeVries 1984) (Fritts 1984) (Swingland 1989) (Van Denburgh 1914)



(Fritts 1983, 1984) (Van Denburgh 1914)

Body Weight: males = 600 - 700 lbs (272 - 317 kg); females = 300 - 400 lbs (136 - 181 kg)
Body Length: Up to approximately 1.8 m (6 ft)

  • Large bony plates on carapace; shell and skin black or dark brownish-gray; large, stumpy extremities with dry, scaly skin;  5 front claws, 4 on back; beaked, toothless jaw.
  • Morphological differences between populations (subspecies) were noted by Captain Porter (1812-1814 ship's journal), well before Darwin visited the Galapagos in 1835.
  • Large amount of individual variation in size and shape seen in all subspecies
  • Main morphological types
    1. Saddle-shaped, flat carapace, long neck, larger distance between plastron and front of the carapace, which is angled upwards, smaller in overall size, yellowish color on lower mandible and throat.
    2. Domed carapace with taller profile, shorter neck and limbs, front of carapace not as steeply angled, larger body size
    3. Intermediate between saddle and dome shape
  • Examples of the dome and saddle-shaped shells.
  • When saddlebacks are frightened and pull into their shell, a large unprotected gap remains at the top of their carapace; predators may exploit this opening
  • Bile acids in turtles have chemical signatures different from those of all other vertebrates, possibly reflecting their ancient divergence from other reptiles. (McArthur et al 2004)


Tortoise skin.
Sexual Dimorphism (Bonin et al 2006) (Van Denburgh 1914)

(Darwin 1898) (DeVries 1984) (Fritts 1984) (Hayes et al.1988) (MacFarland 1972) (MacFarland & Reeder 1974)
(Schafer & Krekorian 1983) (Swingland 1989) (Van Denburgh 1914)

Activity Cycle
Aggression (Fritts 1984) (Schafer & Krekorian 1983) Communication

(Fritts 1984) (Schafer & Krekorian 1983) (Auffenberg 1977)         Vocalization Locomotion Interspecies Interaction

(Bonin et al. 2006) (MacFarland 1972) (Swingland 1989) (Van Denburgh 1914)

(Darwin 1898) (De Vries 1984) (MacFarland et al. 1974) (Rostal et al. 1998) (Russello et al. 2007) (Swingland 1989)

Incubation: 120 - 240 days

Life Stages



        Adults Longevity Mortality Captive Breeding

(CDFG 2003) (Shaw 1967) (Zoonooz 1928, 1978, 1997)

(Caccone 1999) (Caccone et al. 2002) (CDFG website 2003)
(Ciofi 2002) (GCT website 2003) (MacFarland et al. 1974b) (Milinkovitch et al. 2004) (Parham 2008) (Russello et al. 2005) (Russello et al. 2007) (Swingland 1989) (Van Denburgh 1914) (Watkins & Cruz 2007)

Population Status Conservation Threats to survival
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