Leopard Sharks vs. Sevengill Sharks: Identification and Safety for San Diego Spearfishers

If you’re spearfishing off San Diego, you’ll encounter sharks. Most encounters are uneventful, but knowing the difference between leopard sharks and sevengill sharks—and understanding their behavior—keeps you safe and informed.

Leopard Sharks: The Common Encounter

Leopard sharks (Triakis semifasciata) are the most frequently spotted sharks in San Diego waters. You’ll find them year-round, particularly in bays, kelp beds, and shallow reefs from Mission Bay to the Mexican border.

Identifying leopard sharks:

• Size: 3–4 feet on average; rarely exceed 5 feet
• Coloration: Gray-brown back with distinctive black spots and bars on their sides
• Body shape: Slender, streamlined profile
• Fins: Small, proportional dorsal fin
• Head: Pointed snout

Leopard sharks are ovoviviparous (they give live birth), and females gravid with pups appear swollen. You’ll see them cruising the shallows in summer months, especially in Mission Bay and San Diego Bay, hunting small fish and crustaceans.

Behavior: Leopard sharks are docile. They’re curious but not aggressive toward divers. Encounters are common at spots like Sunset Cliffs and the kelp beds off La Jolla Shores, and they typically flee when approached. They pose virtually no threat to spearfishers.

Sevengill Sharks: The Rare but Serious Encounter

Sevengill sharks (Notorynchus cepedianus) are larger, more powerful predators. They’re less common in San Diego waters than leopard sharks, but they appear seasonally and deserve respect.

Identifying sevengill sharks:

• Size: 6–10 feet typically; can exceed 12 feet
• Coloration: Dark gray or brown back, lighter belly with dark spots
• Body shape: Stocky, robust, muscular
• Fins: Larger, more prominent dorsal fin; broad pectoral fins
• Head: Blunt snout; broad, flat head
• Gill slits: Seven on each side (most sharks have five)

The seven gill slits are the definitive marker. If you see them, you’ve got a sevengill.

Behavior and seasonality: Sevengills are apex predators that hunt fish, rays, and occasionally seals. They’re more common in deeper water and canyon systems, but they move into nearshore zones seasonally. In San Diego, sevengill presence peaks in fall and winter, particularly October through March. The canyons near Point Loma, the waters off Ocean Beach, and deeper kelp beds see occasional sevengill activity during these months.

Sevengills are bold and curious. They’re not inherently aggressive, but they’re confident hunters and will investigate unusual activity. Unlike leopard sharks, they don’t automatically flee divers.

Safety Considerations for Spearfishers

Leopard shark encounters: Keep spearfishing as usual. Leopard sharks avoid conflict. If one approaches, a calm, controlled ascent or lateral movement is sufficient. They’re not a safety concern.

Sevengill encounters: These require caution. If you spot a sevengill:

• Maintain awareness: Keep the shark in sight. Don’t turn your back.
• Move deliberately: Ascend slowly and steadily. Avoid erratic, panicked movements.
• Protect your catch: If you’ve speared fish, consider abandoning the catch if a sevengill shows persistent interest. A thrashing, bleeding fish attracts predators.
• Don’t corner it: Give the shark an exit route. Trapped animals are unpredictable.
• Exit the water: If the shark’s behavior escalates (rapid approach, circling, mouth opening), exit calmly and alert others.

Seasonal Patterns and Timing

Summer (June–August): Leopard sharks dominate shallow bays. Sevengills are rare nearshore. Optimal spearfishing conditions with minimal large-shark risk.

Fall (September–November): Sevengill presence increases. Water cools, baitfish move, and larger sharks follow. Exercise heightened awareness.

Winter (December–February): Sevengill season peaks. Visibility can be poor, complicating identification. Stick to well-lit, familiar dive sites.

Spring (March–May): Sevengill presence decreases. Leopard sharks remain steady. Conditions improve.

Practical Takeaways

• Learn the seven-gill marker: It’s the most reliable field ID for sevengills.
• Know the season: October through March warrants heightened vigilance.
• Dive with a buddy: Always. Shark encounters are manageable with a partner.
• Avoid dawn and dusk: Low-light conditions increase predator activity and reduce your ability to identify species.
• Use the Element app: Check real-time shark sighting reports, water temperature, and visibility before heading out to Mission Bay, La Jolla Shores, Sunset Cliffs, or Point Loma. Conditions shift fast in San Diego, and knowing what’s happening in the water right now keeps you fishing smarter.

Both leopard and sevengill sharks are part of San Diego’s marine ecosystem. Respect them, identify them correctly, and you’ll have years of safe, productive spearfishing ahead.