Leopard Shark (Triakis semifasciata) and Spotted Gully Shark (T. megalopterus) Fact Sheet: Physical Characteristics

Body measurements

Sources
Leopards shark: Miller and Lea (1972); Smith and Horeczko (2008); Ebert et al. (2013), Carlisle et al. (2015)
Spotted gully shark: Smale and Goosen (1999)

*Individuals over 183 cm (72 in) unusual (Love 1996)
**One record of a 210-cm (83 in) female (Smith and Horeczko 2008)

Leopard shark

• Body and tail
  • Long, slender, and flexible body (Porter et al. 2011)
  • Vertebral counts: 129-150 (Ebert 2003)
  • Elongated tail (caudal) fin (Ebert 2003)
  • Wide pectoral fins—critical for maneuverability (Soekoe 2016)
• Coloration
  • Ranges from silvery gray to bronzy gray-brown on back (Ebert 2003; Castro 2011)
  • Variable patterns of large, dark “saddles,” interspaced with spots (Castro 2011)
    • Adults tend to have more spots (Ebert 2003)
    • Saddles darker in juveniles (Ebert 2003), lighter in adults (Ebert et al. 2013)
    • Some individuals with “streaks” (longitudinal stripe-like markings) running down their sides or numerous small spots, instead of saddle markings (Castro 2011)
  • Pale or tan underside; no markings (Ebert 2003; Castro 2011)
  • At times, color has a metallic appearance; changes with light and the angle at which the leopard shark is viewed (Castro 2011)
  • Albinism rare, but reported (Ackerman 1971; Ebert 2003)
• Skin
  • Tooth-like scales (“dermal denticles”) described as “sparse,” with little overlap (Castro 2011)
    • Shape resembles a leaf: curved, then tapering to the posterior edge (rear edge, pointing to the tail)
    • Most scales without much of a central ridge
• Head
  • Short, blunt, round snout (Ebert 2003)
  • Flat, wedge-shaped head (Compagno 2003)
  • Oval-shaped eyes (Ebert 2003)
  • Spiracles (openings for breathing behind the eyes) are present (Ebert 2003)
  • Broadly arched mouth (Ebert 2003)
• Teeth (Ebert 2003; Castro 2011)
  • Long, central cusp with one or two smaller cusp points to each side
  • About 50 (range: 41-55) teeth in the upper jaw, 38 (range: 34-45) teeth on the lower jaw

Spotted gully shark  

• Body and tail
  • Slender, streamlined body, similar to other houndsharks (Soekoe 2016)
  • Large, broad fins (Ebert et al. 2013)
  • Where populations more adapted to using sandy habitats, some observed to have a more streamlined body (compared to populations adapted to rocky reefs) (Soekoe 2016)
• Coloration
  • Above, gray-bronze (Soekoe 2016)
    • Usually with many small black spots (Ebert et al. 2013)
  • Below, white/light (Ebert et al. 2013)
  • Young with no or few spots; some adults without spots (Ebert et al. 2013)
• Head
  • Round head and broad, blunt snout (Ebert et al. 2013; Soekoe 2016)
  • Flat, wedge-shaped head (Compagno 2003)
  • Large mouth (Soekoe 2016)
  • Greenish-yellow eyes (Smith 1849)
• Teeth
  • Small, pointed teeth; single point which is slightly angled (Ebert et al. 2013)
  • Teeth close together, but do not overlap (Compagno 2003)
  • Tooth counts: unknown (Ebert et al. 2013)

Leopard shark

• Females grow larger than males (Kusher et al. 1992)
• Talent (1976) observed no apparent differences in diet between males and females

Spotted gully shark

• Females grow larger than males (Booth et al. 2011)
• Soekoe (2016) found almost no differences in body structures between males and females

Triakis species: body size and shape

• Similar to smoothhound sharks (Mustelus spp.) in appearance, but with a larger body size (Castro 2011; Maduna et al. 2017)

Leopard shark

• The leopard shark’s striking markings distinguish it from most other sharks, but its markings sometimes cause confusion with the swell shark, Cephaloscyllium ventriosum (Castro 2011)

Spotted gully shark

• When reporting catch, anglers known to misidentify Triakis megalopterus as Mustelus mustelus or M. palumbes, either by mistake or on purpose (loophole for illegal take); makes reports of shark landings less accurate (Dicken et al. 2012; Best and Attwood 2013)
• Similar species in southern Africa (Dunlop and Mann 2014, except as noted)
  • Smoothhound shark, Mustelus mustelus
  • Whitespotted smoothhound shark, Mustelus palumbes
  • Hardnose houndshark, Mustelus mosis
  • Flapnose houndshark, Scylliogaleus quecketti
  • Blackspot smoothhound, Mustelus punctulatus (northern Africa) (Ebert et al. 2013)
• Similar species on other continents (Ebert et al. 2013)
  • Spotted houndshark, Mustelus maculata
  • Banded houndshark, Triakis scyllium

Leopard shark

• Metabolically, are less sensitive to extreme temperatures, compared to some fishes (e.g., bat ray) (Miklos et al. 2003)
  • Well-adapted to foraging over newly exposed mudflats (heated by the sun) during rising tides (Miklos et al. 2003)
  • After spending time in warm water, can make short foraging excursions into cool water and not experience a substantial decrease in body temperature; beneficial for hunting (Hight and Lowe 2007)
• Well-adapted to poorly oxygenated waters (Ebert et al. 2013)
• Older sharks grow slowly (Ebert et al. 2013)
• Schaffer et al. (2006) showed that juvenile leopard sharks show resistance to domoic acid, a potent neurotoxin that bioaccumulates in invertebrates and fish
• Spiral valve counts: 7-8 (Ebert 2003)
• Lai et al. (1990) compared the heart function of the leopard shark to that of mammals
• Like other sharks, a leopard shark’s skin can become darker after exposure to the sun’s rays (“suntan”), usually from spending time in clear, shallow water (Hight and Lowe 2007)

Both species

• Nictitating lower eye membranes present; provides eye protection when foraging on the bottom or on reefs (Compagno 2003)

Leopard sharks have dark "saddles" and spots on their back.

Markings differ among individuals and can be used to tell them apart.

Image credit: nugunslinger via Wikimedia Commons, cc-by-2.0

Image location: Aquarium of the Bay

Head of a leopard shark.

Several sensory organs can been seen on a shark's head: eyes adapted for light and dark conditions, nostril flaps that help a shark smell, and tiny pits that make up a shark's electrosense.

Image credit: © Yury Velikanau via Wikimedia Commons, cc-by-2.0