acase@tulane.edu

acase@tulane.edu

Two sympatric Sphaerodactylus species (S. clenchi and S. sp.) from the Samana Peninsula of Hispaniola were chosen to study the adaptive tactics of resource allocation (repair versus reproducation) within a body. Tail regeneration was used to indicate repair effort. A theoretical model showing the relationships between repair and reproductive outputs was proposed for the analyses of the results Basic life history and general ecological data were gathered by an ecological survey in the study area, and by raising live animals in the laboratory. The comparisons of reproductive stages and the outputs of reproduction and repair among the females and males whose tails were induced to autotomize at different sites of the tail were used to study the resource utilization patterns. Tritium leucine was used as a tracer to indicate the relative amounts of outputs They were living in similar habitats and had a very high occurrence of tail loss (> 90%) in the field. Compared to S. sp., S. clenchi had a slightly larger body size, a higher growth rate, and also had a much wider geographical distribution. Both species had very similar life history traits in the laboratory Two types of resource allocation patterns were revealed by S. clenchi and S. sp. When more than half the tail is lost, S. clenchi shunts its main energetic effort to repair the lost tail but S. sp. still sets its energetic priority on continuing reproduction A C-S (Colonizers-Specialists) selection continuum comparable to the r-K selection continuum is proposed and used in the discussion of the evolution of resource allocation patterns of Sphaerodactylus in the West Indies. S. clenchi and S. sp. represent two different regimes of the C- and S-selections. An overview of evolutionary mechanisms summarizing the relationships among the ecological and physiological parameters is provided for further studies / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Light and electron microscopic study of the medulla terminalis X-organ (MTXO), medulla terminalis (MT), and the sinus gland (SG) of the fiddler crab, Uca pugilator, showed the SG to be supplied by a distinct nerve tract which originated from 36-40 type 1 cells of the MTXO. At the base of the SG, the sinus gland nerve (SGN) contained 67 (SD = 5.5, n = 3) axons. As it originated from the X-organ, the SGN contained 41 (SD = 3.5, n = 6) axons. The SG, SGN, type 1 cells of the MTXO, and three or four cells near the SG in the MT neuropil were the only organs or cells to stain significantly with paraldehyde fuchsin In the neuropil adjacent to the MTXO, X-organ-sinus gland (XO-SG) tract axons contained NSG 50-200 nm in diameter. Near these axons, other axons contained smaller diameter (50-70 nm) granular vesicles which synapsed on neurosecretory axons, thus providing a source of central nervous system control of the XO-SG tract via aminergic neurotransmitters Treatment of medulla terminalis neuropil (MTN) with the modified chromaffin reaction (MC reaction) (a cytochemical technique to demonstrate aminergic vesicles) preserved granular vesicles (50-75 nm in diameter) with electron-dense reaction product. Other axons in the MTN adjacent to the X-organ contained uniformally dense granular vesicles 35-70 nm after fixation by the MC reaction. Approximately 5% of the granular vesicles were 90-100 nm in diameter MT tissue treated with reserpine and fixed for the demonstration of amines (MC reaction) contained axons with electron-dense reaction product. However, granular vesicles with reaction product were distorted or the quantity of reaction product in vesicles was reduced. Other axons showed an increase in clear synaptic vesicles along with a decrease in reaction product. Therefore because the reaction product in granular vesicles could be modified by reserpine treatment, the method of Tranzer and Richards (1976)--the modified chromaffin reaction--was selective for amines in the MT of U. pugilator / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu