Data are presented on the life history of snake pricklebacks, Lumpenus sagitta, collected in Yaquina Bay, Oregon, from June 1977 to October 1978. Specimens were collected primarily by beach seine from four sampling sites in the bay. Snake pricklebacks feed on algae (mainly genus Enteromorpha), on polychaeta (mainly genus Neoamphitrite), on crustacea (mainly harpacticoida), and other bottomdwelling organisms. They were non-selective in feeding. Based on gonado-somatic indices and egg diameter, I found that snake pricklebacks probably spawn near the end of fall and during winter. Fecundity was positively correlated with standard length of the fish and had a correlation coefficient of 0.85. The number of eggs per fish varied from 2,277 to 6,100 with a mean fecundity of 4,089 eggs. Otoliths are more useful than scales for determining the age of the snake pricklebacks. There is agreement between ages as established by the length-frequency method and those established by the otolith method only until age two. The length-weight relationship was described by the model Ln W = Ln a + b Ln L. The value of the constant "b" was lower than 3.0 for both males and females and varied from 2.33 to 2.78. Females showed a larger constant "b" than males during both years of sampling. Length and weight was correlated for males and females and for sexes combined with "r" values ranging from 0.94 to 0.98. In static bioassays, low salinities (<1.0 ppt) and high temperatures (>20.0 C) deleteriously affected the survival of snake pricklebacks. / Graduation date: 1980

Abstract There are 22 species of chaetognaths belonging 11 genera and 4 families found in coastal waters around the Kaohsiung and Liuchiu Yu Island from March 1997 to February 1998. The average abundance of chaetognaths was 2527 ¡Ó1659 ind./100m3. The 5 most dominant species were Flaccisagitta enflata, Aidanosagitta crassa, Sagitta bipuncata, Ferosagitta ferox and Serratosagitta pacifica, and comprised > 95% of total chaetognaths. Fl. efnlata was the most common and abundance species, its number occupied 70% of total chaetognaths and occurred in every station. These dominant species showed significant seasonal succession, in that, Fl. Enflata could be found in all seasons, while S. bipuncata was found only in fall and winter. Most of chaetognaths found in this study were pelagic, tropical and temperate species, and most of them are widely distributed in the Pacific, the Atlantic and the Indian ocean (50% of total species), and in the Indian and the Pacific ocean (41% of total species). In terms of ecological distribution patterns, warm euryhaline species (i.e. Fl. Enflata and Fe. ferox), and warm hyperhaline species (i.e. S. bipuncata and Se. pacifica) dominated in this study areas. The abundance of chaetognaths was higher in fall (4721 ¡Ó8435 ind./100m3) and the lower in spring (1077 ¡Ó995 ind./100m3). The horizontal distribution of chaetognaths was apparently influenced by the runoff of Kaohsiung Habor and Kaoping River, and the peak abundance was usually found in the front of Kaoping river plume. Most chaetognaths (over 60% of total amount) were found in the surface waters (0-5 m), and its abundance abruptly decreased with depth. The scales of day/night vertical migration of chaetognaths were small (generally less than 50 m). Three types of vertical migration were distinguished in this study: Nocturnal migration (i.e. Fl. Enflata and Se. pacifica). Reverse migration (i.e. S. bipuncata ), and Non-migration (i.e. Fe. ferox). The vertical distribution and the distance of vertical migration of most chaetognaths, however, varied seasonally.

No description available.

No description available.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1965. / Bibliography: leaves 186-193. / xix, 193 l graphs, maps, tables, mounted photos

The chaetognath Sagitta enflata dominates the standing stock of macrozooplankton,and of planktonic carnivores, in the southern basin of Kaneohe Bay. During 1973-74, sampling with vertical net hauls showed no horizontal patchiness in the population. The abundance varied temporally, mainly over periods of months; shorter-term variations were similar to those expected between replicate hauls. Between 1968-69 and 1973-74, both the stock and the dominance of Sagitta in the community increased; both may be related to enrichment of the basin with sewage. Individual Sagitta eat an average of seven prey items per animal per day. The ration in terms of nitrogen or other weight measures varies with animal length, larger Sagitta ingesting more material each day, but smaller Sagitta ingesting a larger fraction of their own body weight daily. Sagitta's predation has little impact on the prey populations, other than Oikopleura, which is the main food of larger Sagitta. Sagitta excretes ammonium and phosphate at rates roughly similar to other zooplankton of similar size. When feeding is prevented during excretion experiments, the specific excretion rates decrease rapidly with time, approaching those observed in laboratory-starved animals. Like other zooplankton, Sagitta has higher N/P ratios in its body tissue than its prey; its soluble excreta thus have a still lower ratio. Despite its abundance and dominance of macroplankton stock, Sagitta is only a minor contributor to nutrient regeneration in the southern basin, which is to be expected, based on its trophic position. The population's rates of growth and mortality were considerably higher than the net change in the stock during most periods analyzed. The instantaneous rates of birth and death are strongly correlated, suggesting a feedback mechanism regulating the population. The population incorporates carbon at about 1% of the rate of primary production in the basin. This is consistent with ecological efficiencies of 10% at each of the two steps froln producers to herbivores to Sagitta's position as the dominant primary carnivore among the plankton. Most of Sagitta's production is probably consumed by predators in the southern basin. The major predator may be nehu, a fish taken for tuna bait from this and other nearby environments. With the planned diversion of sewage from the basin, it is likely that both the stock and the dominance of Sagitta in the southern basin will decrease. / Thesis for the degree of Master of Science (University of Hawaii at Manoa). Typescript. Bibliography: leaves 140-147.

No description available.

No description available.

The aim of this thesis was to identify mugilid stocks in the Southwestern Atlantic coast (25°30'S-40°32'S) and in the Mediterranean coast of the Valencia Community (38º08'N-40°38-N), and their connectivity using the morphology, morphometry and chemical composition of sagittae otoliths (complex carbonate structures located in the inner ear of the fish). Morphology of sagittal for 9 Mugilidae species was analyzed; thus, being able to differentiate them and generating an identification key for the species. Moreover, morphological patterns for family and genera were proposed. Given that otoliths vary along fish growth, ontogenetic patterns were identified for Mugil liza, Mugil cephalus and Liza ramada, describing, also, their biometric relations (standard fish length vs length-width of the otolith). In regard to the identification of fish stocks, by means of morphometrical indices (circularity, rectangularity, aspect ratio, percentage occupied by the sulcus, ellipticity and form factor) and otolith microchemistry (Sr:Ca and Ba:Ca ratios), different behavioral patterns related to habitat use of M. liza and M. cephalus were identified. For M. cephalus four behavioral patterns could be identified with differential use of marine, estuarine and freshwater environments; while for M. liza only three could be recognized. M. cephalus showed at least two fish stocks in the Valencian Mediterranean coast, whereas M. liza did not show michochemical differences that allowed recognizing more than one fish stock in the Southwestern Atlantic coast. In this context, otoliths turned out to be an important complementary tool to study the biology and ecology of mugilids, recognizing movements, habitat use and stock identification; allowing to generate proper management strategies for the species and the preferred used areas. / El objetivo de esta tesis fue determinar los stocks de mugílidos presentes en la costa Atlántica sudoccidental (25°30'S-40°32'S) y en la costa Mediterránea de la Comunidad Valenciana (38º08'N-40°38-N) y su interconectividad, utilizando la morfología, morfometría y composición química de los otolitos sagittae (cuerpos policristalinos compuestos por carbonato de calcio alojados en el oído interno del pez). Se analizó la morfología del sagitta de 9 especies de mugílidos, lo que permitió diferenciarlos y generar una clave de identificación especifica. Asimismo, se propusieron patrones morfológicos del otolito a nivel de familia y géneros. Dado que los otolitos varían a lo largo del desarrollo de los peces, se identificaron patrones ontogenéticos en relación al crecimiento del pez para Mugil liza, Mugil cephalus y Liza ramada, pudiendo describirse las relaciones biométricas (longitud estándar vs largo-ancho del otolito). En relación a la identificación de stocks pesqueros, mediante el uso de índices morfométricos (circularidad, rectangularidad, aspecto de radio, porcentaje del otolito ocupado por el sulcus, elipticidad y factor de forma) y la microquímica del otolito (relaciones Sr:Ca y Ba:Ca) se identificaron diferentes patrones de comportamiento y de uso de hábitats de M. liza y M. cephalus. Para M. cephalus fue posible identificar cuatro patrones comportamentales con uso diferencial de ambientes marinos, estuarinos y de agua dulce, mientras que para M. liza se identificaron solo tres. M. cephalus presentó al menos dos stocks pesqueros en la costa Mediterránea Valenciana, mientras que M. liza no presentó diferencias en la microquímica que permitan reconocer más de un stock en costa del Océano Atlántico sudoccidental. En este contexto, los otolitos resultaron ser una herramienta complementaria importante para el estudio de la biología y ecología de los mugílidos, para el reconocimiento de sus desplazamientos, uso de hábitat e identificación de stocks pesqueros; permitiendo así contar con elementos para realizar un manejo apropiado de las especies y las áreas que utilizan. / L'objectiu d'aquesta tesi va ser determinar els estocs de mugílids presents en la costa Atlàntica sud-occidental (25°30'S-40°32'S) i en la costa Mediterrània de la Comunitat Valenciana (38º08'N-40°38-N) i la seua interconectividad, utilitzant la morfologia, morfometria i composició química dels otòlits sagitta (cossos policristal·lins compostos per carbonat de calci allotjats a l'oïda interna del peix). Es va analitzar la morfologia del sagita de 9 espècies de mugílids, la qual cosa va permetre diferenciar-los i generar una clau d'identificació específica. Així mateix, es van proposar patrons morfològics de l'otòlit a nivell de família i gènere. Atès que els otòlits varien durant el desenvolupament dels peixos, es van identificar patrons ontogenètics en relació amb el creixement del peix, per a Mugil liza, Mugil cephalus i Liza ramada, podent descriure's les relacions biomètriques (longitud estàndard front a llarg-ample de l'otòlit). En relació amb la identificació d'estocs pesquers mitjançant l'ús d'índexs morfomètrics (circularitat, rectangularitat, aspecte de radi, percentatge de l'otòlit ocupat pel sulcus, el·lipticitat i factor de forma), i la microquímica de l'otòlit (relacions Sr:Ca i Ba:Ca) es van identificar diversos patrons de comportament i d'ús de l'hàbitat de M. liza i M. cephalus. Per a aquesta última espècie va ser possible identificar quatre patrons comportamentals amb ús diferencial d'ambients marins, estuarins i d'aigua dolça, mentre que per a M. liza es van identificar solament tres. L'espècie M. cephalus va presentar almenys dos estocs pesquers en la costa Mediterrània valenciana, mentre que M. liza no va presentar diferències en la microquímica que permeten reconèixer més d'un estoc en la costa de l'Oceà Atlàntic sud-occidental. En aquest context, els otòlits van resultar ser una eina complementària important per a l'estudi de la biologia i ecologia dels mugílids, per al reconeixement dels seus desplaçaments, i ús d'hàbitat, així com per la identificació d'estocs pesquers; permetent així comptar amb elements per a realitzar un maneig apropiat de les espècies, i les àrees que utilitzen. / Callico Fortunato, RG. (2017). Aplicación de los otolitos en el estudio de la interconectividad de stocks pesqueros de mugílidos de zonas costeras de la provincia de Buenos Aires, Argentina y de la costa Valenciana, España [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79549 / TESIS