(river shrimp) is found in low salinity areas during April and May. Postlarval Penaeus aztecus 
(brown shrimp) enter the estuary in February through April, move into shallow nurseries, and then 
reappear in large numbers in open bay waters during March through July. Penaeus setiferus (white 
shrimp) postlarvae begin entering the estuary in April and juveniles become most numerous in open 
waters during July through November. A small population of Penaeus duorarum (pink shrimp) 
enters as larvae to shallow estuarine nurseries in the fall and juveniles are recaptured in March 
through May in open bay waters. Callinectes sapidus (blue crab) is most susceptible to sampling gear 
in October through April but may recruit almost all year. One species not included in Table 2.5 but 
quite important to the system is Lolliguncula brevis (brief squid). It is a summer inhabitant of higher 
salinity waters (9) and may be an important determinant of community composition as a predator 
(25). 
Vertebrates 
This section encompasses fishes, birds, amphibians, reptiles and mammals, but only fishes have 
been the object of synoptic surveys. 
Fishes—A comprehensive list of the ichthyofauna of the Galveston Bay system encompassed 66 
families, 122 genera and 162 species (26). Freshwater fishes (9 families, 19 species) rarely found in the 
bay were included. Results of a two-year, synoptic trawl survey (27) indicated that, of 96 species 
recorded, six species accounted for 91 percent of the total number of fishes collected: Micropogonias 
undulatus (Atlantic croaker, 51 percent); Anchoa mitchilli (bay anchovy, 22 percent); Stellifer 
lanceolatus (star drum, 8 percent); Leiostomus xanthurus (spot, 4 percent); Cynoscion arenarius 
(sand seatrout, 3 percent); and Arius felis (hardhead catfish, 3 percent). These six species plus Mugil 
cephalus (striped mullet) were responsible for 74 percent of the biomass collected, dominated by 
Micropogonias (37 percent of the weight) over all others (<10 percent each). In general, the same 
small group of 13 species dominated catches in various bay habitats (Table 2.6). The total fish fauna 
was most numerous in April and May (dominated by Micropogonias) and least dense in December 
and January (dominated by Anchoa). Biomass peaks generally occurred May through August 
(Micropogonias, Stellifer), while the biomass of a mixed assemblage was lowest in November. 
Although no surveys have addressed West Bay proper, surveys of Chocolate Bayou (24) and 
Christmas Bay (13) revealed 72 and 83 species of fishes, respectively, with similar dominant species. 
Larval and postlarval fishes often numerically dominate zooplankton collections. The same 
species that later comprise the bulk of the trawl catches are usually the most abundant as plankters 
(17,18, 28). 
Birds—Although no comprehensive study of the avifauna of the Galveston Bay system has been 
conducted, observers and checklists have recorded 139 bird species associated with wetlands and 
bay habitats (29,30). This group of species accounts for 25 percent of the 565 bird species recorded 
for Texas (31). Further, these wetland-related forms do not include the large number of terrestrial 
resident or migratory birds. Three large groups of birds have a significant representation in the 
Galveston Bay system—waterfowl, shorebirds and colonial nesting waterbirds. 
Waterfowl are censused each January during the Mid-winter Waterfowl Survey, a cooperative 
effort between the Texas Parks and Wildlife Department and the U.S. Fish and Wildlife Service. These 
surveys have shown that 60 percent of Texas' wintering waterfowl are found on the upper Texas 
coast, including large populations of Chen caerulescens (snow goose), associated with rice-growing 
regions of the coastal prairies (32). Aerial surveys of the Galveston Bay system for the years 1978 and 
1984 through 1987 have recorded an average of 11,500 waterfowl annually. The five most common 
species observed during these surveys were Anas crecca (green-winged teal), Aythya collaris (ring¬ 
necked duck), Aythya affinis (lesser scaup), Mergus serrator (red-breasted merganser), and Oxyura 
jamaicensis (ruddy duck). Although a total of 32 species of waterfowl has been observed in the bay 
system (Table 2.7), only Dendrocygna bicolor (fulvous whistling duck), Anas fulvigula (mottled 
duck), Aix sponsa (wood duck), and Anas discors (blue-winged teal) are regular breeders in the area. 
The remaining species of waterfowl use the estuary during migration or while overwintering. 
The Galveston Bay system has been identified by the Western Hemisphere Shorebird Reserve 
Network as a regionally significant reserve site (34), denoting support of >5 percent of all mid¬ 
continental shorebird populations during migration. Large populations of migrating or overwinter- 
33 
