The faunal components of the bay system communities are extensive and diverse. Out of almost 200 entries in a check list of invertebrate

species, Shidler (1960) lists the following as abundant or very

abundant:

Jellyfish

unidentified hydromedusae (jellyfish)

cabbagehead jellyfish (Stomolophus meleagris)

The high rate of biological productivity in this bay-estuarylagoon system, and the extensive development of the detrital food chain is reflected in the very large and diverse bivalve populations. No information could be found on the zooplankton of the bay system.

Pullen (1960) compiled a check list of over ninety species of vertebrates from the Galveston bay system which included sharks, fresh water fish, marine fish, and a porpoise.

The list included representatives from all levels of the marine consumer food chain. There are omnivores such as the bull shark (Carcharhinus leucas) and sea catfish (Galeichthys felis), detritus and plankton feeders, such as the striped mullet (Mugil cephalus), merhaden (Brevoortia patronus), carp (Cyprinus carpio), and bay anchovy (Anchoa mitchilli) and a variety of predators including spanish mackerel (Scomberomorus maculatus), atlantic croaker (Micropogon undulatus), and white crappy (Pomoxix annularis). The single species of porpoise included on the list was Tursiops truncatus, the bottle-nosed porpoise.

Another type of community in the bay system is the oyster reef.

Fisher et. al. (1972) describe it as follows: 1/

1/ Pg. 50 of Fisher et. al. (1972).

"A significant environment within Galveston, Trinity, and related bays is reefs built chiefly of the oyster (Crassostrea virginica

These form 23 square miles of reefs ranging in size from small clumps a few feet in width to complexes up to 5 miles in diameter. Reefs vary in plan from circular to elongate, with the smaller reefs tending to be circular and the larger reefs elongate. Where elongate in plan, the axis of the reef is commonly transverse to the dominant current direction. Oysters are sessile or attached organisms and dependent on circulating waters both for food and for removing waste materials. Favored bottoms for oyster-reef development are either fine, stable sands, or stiff, compact muds. Soft mud substrates or shifting sand bottoms are not conducive to reef growth and support. Another important factor in oyster reef

growth and development is water salinity. Oysters exist in a wide range of water salinity from 5 to 30+ parts per thousand."

Hoffstetter (1959) noted at least 29 species of animals associated with the reef community, not including plankton. He listed the most abundant animals as barnacles, bryozoans, and mussels.

Periodically the oyster

Annelid

predator conch, Thais haemastoma, becomes moderately abundant.

worms were also abundant in all reefs studied, and mud crabs and blue

crabs were also common.

Approximate location of reefs, is shown in Fig. 19.