The Natural History of Foster City, California
by James K. Sayre
a draft manuscript
12 May 2005
Chapter 12: Fish and Invertebrate Life in the Bay waters
The Bay has much animal life contained within its waters and on its mudflat margins. .i.Sharks; are considered by some to be the most common form of fish life in the bay. The author spotted a small .i.Leopard Shark;, .i.Triakis semifasciata;, which had washed up on the shore of the bay in Foster City on 12 April 1995. It was about 16 inches in length and was gray-brown in color on the upper portion of its body. The lower side of the body was white in color. It had a series of darker horizontal stripes that ran from side to side.
It had the sharks' characteristic upper and lower fins. The mouth was about an inch and a quarter across, lined with small teeth. The Leopard Shark is in the Family Triakididae, Smoothhounds, Order Carcharhiniformes. Adult males reach five feet in length, while adult females reach seven feet in length.
On 19 April 1995, a three foot long specimen of Leopard Shark was spotted on the beach at Coyote Point County Park in San Mateo. On 20 April 1995 a specimen of Leopard Shark measuring four and a half feet in length was spotted on the beach on Beach Park Blvd. Its mouth was about two inches across, lined with small, but sharp teeth.
Another common shark is the .i.Brown Smoothhound Shark;. It is also called a Sand Shark, because of its tan coloring and because it is often found near sandy areas of the bay.
On 30 May 1995, a .i.Bat Ray;, .i.Myliobatis californicus;, was observed washed up on the local shell beach. It measured about 18 inches across its width and was about 36 inches long including its tail.
There is edible bright green seaweed, kelp or algae, which is probably .i.Sea Lettuce;, .i.Ulva lactuca;, available for the picking from the local shore of the bay.
At low tide, one may observe the familiar barnacle attached to rocks and manmade objects. These tough-shelled animals live the world over and have been the bane of ship owners for hundreds of years. It is a little known fact that the study of variations in barnacle structures was instrumental in Charles Darwin's development of his theory of evolution of species - he spent seven years in the examination of barnacles from over the world [Weiner]. The barnacle is a Crustacean, specifically in the subclass Cirripedia - Barnacles.
The barnacles live in the intertidal zone, that is, between the high tide line and the low tide line. They feed on tiny bits of food matter which they filter from the bay water. The Acorn Barnacle, Balanus glandula, is the most common barnacle seen along our shoreline. It is also known as the Pacific Acorn Barnacle. It can be found attached to rocks, pieces of cement and even large sticks that have become wedged in the intertidal zone. It lives highest up in the intertidal zone. These barnacles are grayish in color and tend to live in groups, which are called hummocks. The barnacles share these partially-exposed rock surfaces with green algae. Another barnacle which may be seen locally is the Brown Barnacle, Chthamalus dalli, which is flatter and smaller than the Acorn Barnacle.
The brown-colored Sponge which washes up on our Bay beach in great quantities in the winter is the Tube Sponge, Leucosolenia [Tierney].
Invertebrates listed by Coyote Point Museum in their displays:
Bay Jelly Fish Class scyphozoa
Beach hopper Orchestoilia spp.
Bent-nosed clam Macoma nasuta
Blue mussel Mytilys edulis
Checkered Periwinkle Littorina scutulata
Common Rock Barnacle Balanus spp.
Common Rock Limpet Collisala scabra
Gem Clam Gemma gemma
Ghost shrimp Calianassa spp.
Gray flatworm Leptoplana spp.
Hermit crab Pagurus spp.
Lugworm Arenicola spp.
Olympic oyster Ostrea lurida
Pink sea anemone Class Arshozoa
Rock snail Nucella lamellosa
Sea squirt Class Ascidiacea
Skeleton shrimp Caprella californica
Soft-shell clam Mya arenaria
Striped shore crab Pachygrapus crassipes
White slipper shell Crepidula spp.
Yellow sponge Phylum parifera
End.
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Web page last updated on 12 May 2005.