Species Profile: Bay Pipefish

Interesting fact from Baykeeper's upcoming Winter Newsletter: San Francisco's Seahorses are not limited to those plastered on the walls in the Powell Street BART Station.

What is a Pipefish?
The Bay Pipefish (Sygnathus leptohynchus) is a member of Syngnathidae – a family of fish that includes Seahorses and Sea Dragons. The Bay Pipefish shares many characteristics with its enigmatic cousins, including plates of bony armor, small tubular mouths, cryptic coloration, and secretive behavior. Like other Pipefish, however, the Bay Pipefish has a long, straight body.

What do they look like?
The Bay Pipefish is a long, thin fish that grows to about a foot in length. Its coloration varies between shades of green and brown. It may be possible that the Bay Pipefish changes its color to match its surroundings, but this is not known for sure. Just like Seahorses and Sea Dragons, the Bay Pipefish has a long tubular mouth formed by fused jaw-bones.


Where are Bay Pipefish found?
The Bay Pipefish inhabits eelgrass beds and shallow estuaries along the Pacific Coast from Baja California to Alaska. Hidden among blades of eelgrass, the long slender fish is almost completely concealed. The eelgrass beds also support an abundance of prey, allowing the Bay Pipefish to thrive. In the Bay Area, the Bay Pipefish can be spotted in eelgrass beds in San Francisco Bay, Suisun Bay, Drakes Estero, and Tomales Bay.

What do they eat?
The Bay Pipefish uses its tubular mouth to suck plankton prey out of the water like a vacuum cleaner, rather than biting it. When it is hunting, the Bay Pipefish remains completely still beneath its prey. Its eyes are capable of binocular vision, allowing it to determine the distance to its prey. When the position is just right, the Bay Pipefish will quickly snap its head up, placing its tiny mouth about an inch from the prey and delivering suction to capture its meal.

How do they reproduce?
Bay Pipefish reproduction begins in the early spring when eelgrass grows and plankton density increases in the water column. Like other male Syngnathids, the male Pipefish has a well-developed brood pouch on the underside of its tail. After the female deposits her eggs within the male's brood pouch, a layer of tissue grows to seal the eggs inside. The male Pipefish carries the embryos for several weeks, providing them with the nutrients, oxygen, and water they need to develop. When ready to hatch, hundreds of Pipefish young split the pouch and emerge into the water, resembling miniature versions of the adults.

What are the threats to Bay Pipefish in the Bay?
The greatest potential threat to the Bay Pipefish in the Bay Area would be the loss of habitat. Luckily for the Bay Pipefish and other eelgrass dependent species, the extent of eelgrass beds in the San Francisco Bay has actually been expanding in recent years. Although there is no commercial fishery for Pipefish species, they are collected for the Chinese medicine trade. At this time Pipefish are abundant, but if the demand for Pipefish by alternative health care markets increases, Pipefish might become as scarce as their Seahorse relatives.

Photo credit: Aquarium of the Bay

Species Profile: Leopard Shark

Interested in San Francisco Bay wildlife? This is a species profile that I wrote on Triakis semifasciata, the Leopard Shark, for our Fall 2009 newsletter. This is the original, soon to be hacked away by the cruel hand of the redactor.

Where are Leopard Sharks found?
Leopard Sharks are found along the Pacific Coast - from Central Mexico to Oregon. One of the most common sharks in California, there is a large population of Leopard Sharks living in the San Francisco Bay. Most of them live in the Bay year round, with a few individuals migrating out in the fall. Leopard Sharks are often spotted near the bottom in the shallow waters of the sloughs and mudflats along the Bay margins. The Bay offers a safe haven for the Leopard Shark, because the water is too shallow and warm for predators, such as the Great White Shark. Plus the Leopard Shark finds abundant prey in the muddy bottom of the Bay. They often follow the high tide up to the shoreline to feed on animals in the shallow mudflats; then they move back out as the water recedes.

What do they look like?
The Leopard Shark is a slender fish with silvery-bronze skin and dark ovals arranged in neat rows across its back. Leopard Sharks are quite small. Their average length is around three to four feet, although they can grow up to seven feet. The Leopard Sharks in San Francisco Bay are more likely to be between two and three feet long.

What do they eat?
Leopard Sharks feast on small invertebrates, such as clams, worms and crabs that they find along the muddy bottom of the Bay. They also like small fish, eggs and the occasional Bat Ray. Sometimes the Leopard Shark can pluck prey right off the mud with its bottom-facing mouth. In other instances, the shark will shovel its nose into the bottom and toss the sediment away, exposing hidden clams or worms. Leopard Sharks may go to extreme lengths to eat small animals, but they will not attack humans.

How do they reproduce?
Leopard Sharks have ovoviviparous reproduction, which means that the baby sharks, or pups, develop in eggs that are retained within the mother’s body. The eggs hatch in the mother’s body, and then the pups are born live. A female Leopard Shark can have up to 29 pups in one litter.

What are the threats to Leopard Sharks in San Francisco Bay?
Leopard Sharks are fished both commercially and recreationally, with recreational fishing accounting for the majority of the catch. Even though it is an abundant species, Leopard Sharks grow so slowly that overfishing could deplete the population. Concerns about overfishing lead to the implementation of size limits by the Department of Fish and Game - Leopard Sharks smaller than 36 inches must be released. Leopard Sharks also contain high levels of mercury in their tissues. These animals have a greater exposure to mercury than other fish species because they spend so much time feeding in contaminated Bay sediments. It is unknown if the mercury is harmful to the Leopard Sharks, but it certainly exceeds the accepted safe limit for humans.

Photo credit: Peter J. Bryant