by Wong Wai-Yee, Dolly. / Bibliography: leaves 90-102 / Thesis (M.Phil.) -- Chinese University of Hong Kong, 1983

Tésis (Biólogo)--Universidad Nacional Autónoma de México, 1961. / Includes bibliographical references (p. 95-96).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 127-136).

Thesis (M. Sc.)--Acadia University, 1997. / Includes bibliographical references. Also available on the Internet via the World Wide Web.

Thesis (M. Sc.)--Acadia University, 1997. / Includes bibliographical references. Also available on the Internet via the World Wide Web.

Thesis (Ph.D.) -- Australian National University, 2007.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : [45]-52).

Foi realizado experimento em laboratÃrio para observar a predaÃÃo do caranguejo mÃo-grossa Menippe nodifrons sobre trÃs espÃcies de moluscos gastrÃpodes: Stramonita haemastoma, Tegula viridula e Neritina virginea. Os aspectos observados foram de preferÃncia alimentar do caranguejo, tempo de manipulaÃÃo e manipulaÃÃo das presas, tamanho crÃtico da presa, e ainda, a anÃlise biomecÃnica das quelas dos caranguejos. Os caranguejos e os moluscos foram coletados na praia do Pacheco, localizada no municÃpio de Caucaia-Ce. Menippe nodifrons alimentou-se das trÃs espÃcies de gastrÃpodes, com uma maior preferÃncia alimentar por N. virginea (n = 62) em relaÃÃo aos outros moluscos oferecidos S. haemastoma (n = 41) e T. viridula (n = 35). A predaÃÃo pelos caranguejos foi maior sobre S. haemastoma, do que em T. viridula. Os machos predaram mais ativamente Neritina virginea, enquanto as fÃmeas nÃo tiveram preferÃncia por nenhuma das presas oferecidas, predando-as indistintamente. O tempo de manipulaÃÃo foi menor para N. virginea (44,2 min.) do que para S. haemastoma (106,1 min.) e T. viridula (120,7 min.). Os moluscos foram manipulados atravÃs de duas tÃcnicas: esmagamento e descascamento. O esmagamento foi predominante em Neritina virginea, enquanto que o descascamento foi usualmente maior em Tegula viridula e Stramonita haemastoma. O tamanho crÃtico da presa foi menor para N. virginea (0,34), seguida por S. haemastoma (0,38) e T. viridula (0,50) respectivamente. O caranguejo Menippe nodifrons apresentou vantagem mecÃnica para as duas quelas (Quela Maior = 0,38) e (Quela menor = 0,32), que os classificam como especialistas em quebrar conchas mais resistentes e duras. As quelas sÃo dimÃrficas e possuem dentiÃÃes diferentes, com atividades funcionais distintas para quebrar as conchas dos moluscos. O comportamento predatÃrio do caranguejo Menippe nodifrons està diretamente relacionado ao nÃvel de especializaÃÃo de suas quelas, das caracterÃsticas morfolÃgicas e vulnerabilidade de suas presas. / experiments were used to study the effect of the predation of the crab Menippe nodifrons on the gastropods Stramonita haemastoma, Tegula viridula and Neritina virginea. Aspects studied were prey preference, handling time, predation techniques, prey critical size and chelal biomechanic analysis of the crabs. The crabs and the clams were collected in Pacheco beach, located in the city of Caucaia-Ce. Menippe nodifrons preferred Neritina virginea over both Stramonita haemastoma and Tegula viridula, and Stramonita haemastoma was strongly preferred over Tegula viridula, possibly because of differences in shell characteristics among the three species. The male crabs preyed more heavily upon Neritina virginea than on both gastropods Stramonita haemastoma and Tegula viridula, while the females had eaten indistinctly the three clams. There were differences in hadling times between Neritina virginea, Stramonita haemastoma and Tegula viridula (handling times: N. virginea < S. haemastoma < T. viridula). Crabs attacked snails using crushing and peeling techniques, the last was used only upon S. haemastoma and T. viridula. The mean critical size for Neritina virginea was significantly smaller than that for Stramonita haemastoma, which in turn was smaller than that for Tegula viridula. The claws of the crab Menippe nodifrons are well designed for breaking shells. Menipppe nodifrons is heterochelous, having one larger crusher claw and one smaller less robust cutter claw. Due to their greater mechanical advantage, crusher claws are able to generate considerably greater forces than cutters. Differences in the morphological and mechanical features of crab claws reflect their function and account for many of the observed differences in prey handling techniques and foraging behavior. Menippe nodifrons seems to be pecialised for attacking hardshelled molluscan prey. The predatory behavior of the crab Menippe nodifrons is directly related to the level of specialization of its claws, of the morphological characteristics and vulnerability of its prey items.

Erratic and highly variable catches in the South African chokka squid Loligo vulgaris reynaudii fishery, cause socio-economic hardship for the industry and uncertainty for resource managers. Catch forecasting can reduce this problem as it is believed that catch variability is strongly influenced by environmental factors. In this study, data were collected at varying temporal and spatial scales. Data for the hourly time-scale study were collected from 1996-1998, aboard commercial vessels, whilst for the longer time-scales, data were extracted for Kromme Bay (a single fishing area) from existing databases (1991-1998) that were comprised of compulsory catch returns and oceanographic data. The environment-catch relationship for chokka squid on the inshore spawning grounds was then investigated using multiple correlation and regression analysis, analysis of variance, contingency table analysis and cross-correlation statistical techniques. This simple, direct, 'black box' statistical approach was relatively successful in developing a predictive capability. On a short time-scale (hourly), the regression model accounted for 32% of the variability in catch, with turbidity the main determinant (13%). On a daily monthly time-scale, the best prediction model was on a monthly scale, accounting for 40% of the variability in catch. The principal determinant, bottom temperature anomaly (11 %), was found to lag one month forward. Seasonal and diel catch variations induced changes in the relative importance of turbidity, water temperature and wind direction on catches. A strong, positive relationship was found between easterly winds (which cause upwelling) and catch, particularly in summer. Catch rates, however, decreased with an increase in turbidity. The correlation between temperature and catch was generally negative, however, higher catches were associated with a temperature range of 13-18°C. Highest catch rates were associated with easterly winds, zero turbidity conditions and sea surface temperatures from 15.0-16.9°C. Selected case studies (in situ observations) suggested that upwelling and turbidity events act as environmental triggers for the initiation or termination of the spawning process, respectively. A holistic approach is required to improve predictive capability of chokka squid abundance. Although short-term predictability remains essential (i.e. hourly-scale), future research should concentrate on long-term prediction models (e.g., monthly time-scales) involving greater spatial variation, which are the most important for management.

Thesis (Ph. D.)--University of California, Riverside, 1995. / Includes bibliographical references (leaves 342-367).