Goldfish (Carassius auratus) of 15-28g were maintained at 23 C and subsequently were intraperitoneally injected with saline (controls) and varying doses of Triiodothyronine (T3). Following the injection, the fish were placed in a thermal gradient and temperature selection and activity monitored for 30 min. There was no- significant difference between the responses of the experimental fish to the 2 different doses of T3. However, there was a significant difference in response between the experimental and control groups (P < 0.001). The decreased temperature selection occurred early in the test runs, while the increased activity began later. Larger goldfish (175-205g) received 0.5 μl intracerebral injections of 1.5-3.0 ng T3 in the anterior brainstem via an indwelling cannula injection system. These fish responded to the injections by selecting cooler water. The magnitude of the response was related to the distance of the injection site from the preoptic/anterior hypothalamic region. I conclude that increased plasma levels of T3 lead to the selection of cooler water. This effect appeared to be mediated via the anterior brainstem. Injected T3 also produced hyperactivity. This latter effect developed more slowly and appeared to be more diffusely mediated.

No description available.

No description available.

The term “delta area” refers to a region roughly 40 miles long and 15 miles wide situated 65 miles east of San Francisco Bay where the San Joaquin and Sacramento Rivers join and enter Suisun Bay. The waterways in this area are fresh water from these rivers, but they are affected by the ocean tides and to some extent by the salinity of the ocean water. The rgeion ecompasses about 507,000 acres, most of which has been reclaimed for agricultural purposes by the construction of levees to contain the tides and high waters. The word “islands” is used locally to designate this area. The part played by beavers in the exploration and colonization of this nation was a very important one. The fur trappers in their quest for new areas in which to trap, vigorously explored unknown regions. Knowledge concerning the geography of the new land was passed on the colonists who were eagerly seeking new and suitable sites for home and farms. Thus did the beaver and other fur-bearing animals indirectly speed the development of the nation.

The following study was conducted from August to November of 1991 on North Pagai Island in the Mentawai Archipelago, Indonesia. The purpose of the study was to obtain preliminary information on the ecology and behavior of the four Mentawai endemic primates: Hylobatcs klossii, Macaca pagensis, Presbytis potenziani, and Simias concolor. All four species are considered endangered due to human activities, especially hunting and various forms of habitat destruction. Therefore, the present critical status of these primates makes their conservation and that of the Mentawai Islands' rain forest a priority. It appears that resource partitioning occurs among the four primate species, M. pagensis occupied all vegetation levels and was less arboreal relative to the other three species which were primarily arboreal. All four species were found in forest habitat with S. concolor also occurring in forest swamp. M. pagensis and P. potenziani were found throughout the study area and only P. potenziani occupied coastal swamp. In addition, it is hypothesized here that for many P. potenziani groups, sleeping trees are located outside of the primary forest and these groups migrate on a daily basis to the forest. As a result, this may reduce interspecific competition since this species and H. klossii overlap in terms of resource use. Group size and composition are discussed and a monogamous social organization was identified for H. klossii and P. potenziani while M. pagensis. was found to form polygamous families. S. concolor is identified as forming one-male polygamous groups, however, based on my observations it might initially be interpreted that this species formed monogamous groups in the study area. Most behaviors, such as parental care, aggression, grooming, play, and feeding behavior, were rarely observed due to the wanness of these primates. Alarm response to detection of humans is discussed and distraction-like behaviors are described for each of the species. Population density was determined for each species and these values corresponded to those found in other studies although all values in this study were relatively low compared to other studies.

Crustacean spermatozoa are among the most peculiarly modified germ cells in the animal kingdom. Many of their striking cytological specializations may be observed in the sperm cells or Emerita analoga, the so-called sand crab. This animal has been used by the writer for studies on spermatogenesis and on spermatozoan behavior during the summer or 1951, 1952, and 1953 at the Pacific Marine Station.

The primary purpose of this research is to further morphological studies on larval ascidians and to encourage greater reliance on larval structures in ascidian taxonomy. This may necessitate some revisions in current classifications, but it is hoped that such revisions will lead to a better understanding of the group. Some general considerations of ascidians are here included for the benefit of those who may not be familiar with them. All specimens used in this study were collected at the Pacific Marine Station area at Dillon Beach, California, during June, July, and August of 1957.

Statement Qf the problem. The green valley grasshopper, Schistoceroa venusta Scudder, is one of the most common grasshoppers to be found in the San Joaquin Valley and environs. Despite the fact that the insect is commonplace, very little work has been done on its biology. It was the purpose of this study, therefore, to learn by field and laboratory observations of the life cycle and habits of Schistoceroa venusta.

The purpose of the work leading to the writing of the thesis was two fold: (1) to survey birds of Northern California for hemoprotozoa of the genera Haemoproteus, Leucocytozoon, and Trypanosoma, and (2) to construct an up-to-date check-list of the Haemoproteus, Leucocytozoon, and Trypanosoma parasites of birds of North America.

Two species of oviparous oysters, Crassostrea virginica (Gmelin, 1790), the Eastern oyster, and Crassostrea gigas (Thunbert, 1793), the Japanese oyster, were introduced into Tomales Bay, California, for commercial purposes. Because these oysters do not propagate in Tomales Bay, new shipments of adult oysters or oyster spat must be periodically sent from the east coast of the United States or from Japan. It is the purpose of this study to compare the seasonal gonadal changes which occur in the two species of adult oysters in Tomales Bay with one another, and to compare them with the seasonal gonadal changes which occur in the same species of oysters in other regions. The differences in gonadal changes will be related to variances in environmental conditions and to specific or racial characteristics. The introduction of oysters into a new environment is valuable for both commercial and scientific reasons. Although it has long been known that C. virginica and C. gigas do not propagate in Tomales Bay, no one has ever done a detailed study of their reproductive cycle or the seasonal histological changes in their gonads. This study, therefore, extends the knowledge concerning an oyster's reaction and adaptation to its new environment.