The present work is an attempt to correlate information collected in the northern part of Chile with the anchoveta distribution and its fluctuation. This information was collected over a three year period (November 1967 to November 1970) by the Instituto de Fomento Pesquero, Chile (IFOP). The first and second part represent an exhaustive review of the biology of the species and the principal oceanographic features of its habitat. It is based upon several years of research conducted by the Instituto de Fomento Pesquero in Chile, the Instituto del Mar del Peru in Peru, and other institutions. Results of these studies are reported through 1972, providing the necessary background for the discussion presented in later chapters. In part three the information collected during the three year period by IFOP is presented. Seasonal average maps of temperature, salinity, transparency, fish distribution, volume of zooplankton, eggs and larvae of anchoveta are presented and discussed. Oxygen and temperature sections are also presented in relation to school distribution, The final part is entirely devoted to a discussion of outstanding features of the interrelationship of the anchoveta to the environment that is found in the region. The effect of temperature appears to be important in the fish distribution and may be responsible for the major concentrations during summer months that result in higher catches by the fishing fleet. Oxygen appears to be of primary importance in the seasonal fluctuations. When upwelling takes place, especially during winter, water with a low oxygen content from the Peru-Chile Undercurrent is brought to the surface forcing the anchoveta to migrate to the west away from the coastal areas. The effect of a highly saline and warm oceanic front may also affect fish distribution. The effect of all these could also affect eggs and larval survival, but the relationships are not clear. The bibliography at the end of the work is a complete bibliographical review on the subject and will be used for further studies in anchoveta off Peru and Chile. / Graduation date: 1973

The Pacific anchovy, Engraulis mordax Girard, occurs in limited numbers in most of the bays and inlets of southern British Columbia where it supports a small purse-seine fishery during the spring and summer months. A study of the age, growth and maturity of this species was carried out by the analysis of samples randomly selected from commercial catches during the years 1947 to 1951. Age and growth studies are based chiefly on the analysis of length frequency distributions and checked by scale readings. The use of length frequencies was facilitated by the presence of one or two dominant year classes in each commercial catch. The reliability of the method is supported by scale readings. Average lengths of 107, 128, 140, 149, and 157 millimetres are calculated for females at 1, 2, 3, 4, and 5 years; and average lengths of 105, 126, 138, 146 and 153 millimetres for males at the same ages. Maximum size of females is found to be 168 millimetres, representing an age of 7 years. Maximum size of males is found to be 153 millimetres, representing an age of 6 years. The incoming year class majority of fish taken in the commercial catches are 2 or 3 years of age. Maturity studies based on measurements of ova diameters show that spawning occurs in most of the bays and inlets in southern British Columbia in late June, July and August, The majority of females mature in their second year, but some may mature in their first year. The situation for males appears to be similar. Growth of the ova begins in adult females of all sizes and from all localities in February and March. By June the majority of females have matured three size groups of eggs preparatory to spawning. Evidence is given that multiple spawnings occur and that each of these size groups of eggs is matured and in turn spawned. No maturing ova are carried over into succeeding years. A minimum average of 144,000 eggs are spawned in three or more batches each year. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 139 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains ix, 137 p. : ill., maps Vita. Includes abstract. Includes bibliographical references.

No description available.

No description available.

Sardines and anchovies are small pelagic fishes that support important commercial fisheries around the world. This project reviews the inverse cyclic behavior in the abundance of these two stocks, which is a striking feature in many regions. In addition, the project used qualitative loop analysis techniques to analyze the feasible sardine-anchovy model configurations that result in the inverse relationship between sardines and anchovies. A simple community model was examined that considers fishing, sardine and anchovy biomass, and food resources for the sardines and anchovies. First, the stability of these model configurations was investigated to determine the conditions that should be met to stabilize the unstable configurations. Second, the behavior of the feasible sardine-anchovy model configurations was examined when fishing was removed from the models. Finally, model configurations were identified that best represent the sardine-anchovy system in terms of predicting qualitative changes in the system variables. These best models define the crucial interactions between sardines and anchovies that require further studies. Based on the results of the literature review and the loop analysis a set of questions was developed and used in interviews with fishers in Oman to investigate whether the sardines and anchovies in Oman are inversely related. Based on the survey results and lessons learned from the literature review and loop analysis, recommendations were developed for further research and management of the fisheries in Oman for sardines and anchovies. In systems where the sardines and anchovies vary inversely in abundance refuge areas for the sardines and anchovies are very important for maintaining the two fish stocks and their cyclic behavior. The results from the loop analysis suggested that interactions between sardines and anchovies (e.g., competition and amensalism) are not important provided the two fish populations can regulate themselves by means of their refuge areas. The expansion and contraction of sardines and anchovies is a function of environment suitability and long-term shifts in the environmental regime. The study found no evidence that sardines and anchovies in Oman are inversely related. / Graduation date: 2003

Huge populations of sardine and anchovy exist in the four major upwelling systems around the world. These fish are both important ecologically and economically. Pelagic fish dominate the mid trophic level and can exert both a top-down control of zooplankton and a bottom-up control on predatory fish and marine top predators. They also make up a substantial contribution of the world catches in seas around the world where they co-exist in upwelling areas. The fluctuations of sardine and anchovy are largely influenced by recruitment from the larval stage and by the physical environmental forces that determine the planktonic compositions upon which they feed. In southern Africa, the biology and behaviour of two threatened seabird species, African penguins (Spheniscus demersus) and Cape gannets (Morus capensis), are directly influenced by the availability of sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus). This study aimed to provide further insight into the fluctuations of sardine and anchovy in relation to the variability of environmental factors such as wind, sea surface temperature, rainfall and plankton abundance, focusing specifically on Algoa Bay in the Eastern Cape, South Africa. Algoa Bay is particularly important as it is home to the world’s largest African penguin colony and the world’s largest gannetry. Therefore, to further investigate the populations of these two seabird species, the fluctuations of their food source were studied.

Made available in DSpace on 2016-04-28T15:01:30Z (GMT). No. of bitstreams: 1 2006-Marcio de Araujo Silva.pdf: 1021649 bytes, checksum: 0b981908af67bec8e46455a6b9a080ca (MD5) Previous issue date: 2006-04-25 / Morphological variation for the anchovy Lycengraulis grossidens (Agassiz, 1829) in 14 sites along the Brazilian coast (Par? to Rio Grande do Sul) were described to quantify the intraspecific heterogeneity, and to test the hypothesis that seeking for adaptability to different areas results in differentiated patterns that characterize isolated populations. A total of 210 individuals from collection from Museums plus donations, were examined, from which 18 morphometric and 5 meristic characters were taken. Three groups (populations) were formed based on morphometrics and one additional group (4 groups) by meristic characters, indicating the presence of 4 populations along the Brazilian coast. Population I, from the Par? coast, inhabit an area of major influence of the Amazon river, showing waters of low salinity and high temperature. Population II, from Cear? to Esp?rito Santo State, has a wider distribution, showing overall similar mophological characters to population I, indicating gene flow between these two populations. Population III comprises fishes between Rio de Janeiro and S?o Paulo States, and show a transition zone with population II well evidenced in the north of Rio de Janeiro, suggesting to be an hybridizing area. Population IV, from Santa Catarina to Rio Grande do Sul, showed the highest number and largest sized gillrakers, being the most morphologically differentiated group. Fishes from low latitudes showed higher body width, head length, cheek length, maxilla length, mouth length and peduncle width compared with fishes from high latitude. Additionally, specimens from Santa Catarina and Rio Grande do Sul showed anal and dorsal fins located in more posterior body position, while anal fin base was larger for specimens form Rio de Janeiro and S?o Paulo, indicating that fishes from this former areas (SC and RS) have higher capacity to move in higher speed when compared with fishes from this latter area (RJ e SP). Concerning to meristics characters, there is an increased number of gillrakers from lower to higher latitudes, coinciding with the expectation of somites addition to occur faster in acceleration condition than under retarding condition, but finish abruptly, resulting in lower number of meristics element in higher temperatures. Several zoogeographic pattern has been described for the Brazilian coast, with the Antillean Province situated at north of Cabo Frio (23oS), a transition area between Cabo Frio (23oS) and the surrounds of Cabo de Santa Marta Grande (28?-30?S), and the Argentine Province up to 35?S, with this division closely coinciding with L.grossidens populations distribution in this study, except for the Para coast, where we recognize a differentiated group. / Varia??es morfo-meristicas da manjuba Lycengraulis grossidens (Agassiz, 1829) em 14 localidades da costa brasileira (Par? ao Rio Grande do Sul) foram descritas com o objetivo de quantificar a heterogeneidade intra-espec?fica, visando testar a hip?tese de que a adaptabilidade em ?reas diferentes resulta em padr?es diferenciados que caracterizem diferentes popula??es. Foram examinados 210 indiv?duos oriundos de cole??es depositadas em Museus e complementadas com doa??es, dos quais foram tomados 18 caracteres morfom?tricos e 5 mer?sticos. Tr?s grupos (popula??es) foram formados com base nos caracteres morfom?tricos e um grupo adicional (4 grupos) por caracteres mer?sticos, indicando a presen?a de 4 popula??es ao longo da costa brasileira. A popula??o I, do litoral do Par?, habita uma ?rea sob grande influ?ncia do rio Amazonas, com ?guas de baixa salinidade e alta temperatura. A popula??o II, que se estende do Cear? ao Esp?rito Santo, ? a de distribui??o mais ampla, apresentando em geral caracteres morfol?gicos semelhantes aos da popula??o I, o que poderia indicar a exist?ncia de fluxo g?nico entre as mesmas. A popula??o III compreende os peixes distribu?dos entre Rio de Janeiro e S?o Paulo, e apresenta uma zona de transi??o com a popula??o II bastante evidenciada no norte do Rio de Janeiro, aparentando ser esta ?ltima uma ?rea de hibridiza??o. A popula??o IV, de Santa Catarina e Rio Grande do Sul, apresenta como caracter?sticas mais marcantes o n?mero e o comprimento dos rastros branquiais, sendo o grupo morfologicamente mais diferenciado. Peixes de baixas latitudes apresentaram maior altura do corpo, comprimento da cabe?a, comprimento da face, comprimento da maxila, comprimento da boca e altura do ped?nculo caudal, comparados aos peixes de altas latitudes. Adicionalmente, os esp?cimes da popula??o IV apresentaram nadadeira anal e dorsal localizadas em posi??o mais posterior do corpo, enquanto a base da nadadeira anal foi maior em esp?cimes do Rio de Janeiro e S?o Paulo, indicando que peixes da popula??o IV possuem maior capacidade de se deslocar em velocidade quando comparados com peixes do Rio de Janeiro e S?o Paulo. Em rela??o aos caracteres mer?sticos verificou-se um aumento do n?mero de rastros branquiais das menores para as maiores latitudes, coincidindo com a expectativa de que a adi??o de somitos ocorre mais rapidamente sob condi??es de acelera??o do que sob condi??es retardantes, mas termina mais abruptamente, resultando em menor n?mero de elementos mer?sticos em temperaturas mais altas. V?rios padr?es zoogeogr?ficos t?m sido sugeridos para a costa brasileira, com a Prov?ncia Antilhana situada ao norte de Cabo Frio (23oS), uma ?rea de transi??o entre Cabo Frio (23oS) e o os arredores Cabo de Santa Marta Grande (28?-30?S), e a Prov?ncia Argentina at? 35?S, com esta divis?o da costa de certo modo, coincidindo com as distribui??es das popula??es de L.grossidens encontradas no presente trabalho, com exce??o da ?rea costeira do Par?, onde reconhecemos um grupo diferenciado.