Ecology of larval fishes around reefs in the Gulf of California, Mexico.

Persistent Link:
http://hdl.handle.net/10150/185972
Title:
Ecology of larval fishes around reefs in the Gulf of California, Mexico.
Author:
Brogan, Michael William.
Issue Date:
1992
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
My research has focused on the identification, assemblage dynamics, and horizontal distribution patterns of larval fishes around rocky reefs in the Gulf of California, Mexico. In Chapter One, I analyze a series of light-trap collections taken over 35 nights at San Carlos, Sonora. Nearly 14,000 larvae from 19 families were collected. The five most abundant families contributed 90% of the larvae and the top ten families contributed 99%. Larvae of non-pelagic spawners (gobiids, labrisomids, tripterygiids, chaenopsids, pomacentrids, and bythitids) dominated the collections. Larval catches ranged from 7.5 to 2330.3 larvae/45 min, but changes in catch rate were not related to changes in ambient moonlight. In contrast, the volume of zooplankton collected was correlated with moonlight intensity. Dynamics of the ten dominant fish families were highly variable, but in most cases a large proportion of the larvae were caught on just a few nights. Taxonomic and size selectivities were apparently less severe in my study than in previous Australian studies, and the use of light-traps should be explored further. In Chapter Two, I outline the prediction that larvae of small, non-pelagic spawning fishes should more frequently be retained over reefs during development than fishes with other combinations of body size and egg type, and I describe my research testing this prediction. I made about 160 collections of fish larvae with a light-trap and plankton net at 1, 20, and 100 m from rocky shorelines. These collections yielded 27,265 larvae from about 50 families. Based on larval size frequencies, near-reef concentration gradients, and abundances offshore, I identified four families that can complete development over the reef but also have larvae dispersed offshore (Clupeidae, Engraulididae, Gerreidae, and Haemulidae). In addition, I identified seven families that primarily develop over reefs and have few or no larvae dispersed offshore (Tripterygiidae, Chaenopsidae, some Labrisomidae, Dactyloscopidae, some Gobiidae, Gobiesocidae, and Bythitidae). Adults of these seven families are mostly small, non-pelagic spawners. Larvae from four taxa of larger non-pelagic spawners (Ophioblennius, Labrisomus, Balistes, and Pomacentridae) did not appear to develop over reefs. These findings are in accord with the prediction I made. Chapter Three is a preliminary guide to identification of Gulf of California blennioid larvae. Although blennioid larvae are poorly known and few species have been described, they are well represented (ca. 20,000 larvae from five families) in my collections taken near reefs in the Gulf. Illustrations of 20 species, and brief descriptions of key characters for these and several additional species, are provided. More detailed taxonomic studies on Gulf blenniid, dactyloscopid, tripterygiid, labrisomid, and chaenopsid larvae are in progress.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Fishes -- Larvae.; Fishes -- Mexico -- California, Gulf of.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Ecology and Evolutionary Biology; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Thomson, Donald A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleEcology of larval fishes around reefs in the Gulf of California, Mexico.en_US
dc.creatorBrogan, Michael William.en_US
dc.contributor.authorBrogan, Michael William.en_US
dc.date.issued1992en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractMy research has focused on the identification, assemblage dynamics, and horizontal distribution patterns of larval fishes around rocky reefs in the Gulf of California, Mexico. In Chapter One, I analyze a series of light-trap collections taken over 35 nights at San Carlos, Sonora. Nearly 14,000 larvae from 19 families were collected. The five most abundant families contributed 90% of the larvae and the top ten families contributed 99%. Larvae of non-pelagic spawners (gobiids, labrisomids, tripterygiids, chaenopsids, pomacentrids, and bythitids) dominated the collections. Larval catches ranged from 7.5 to 2330.3 larvae/45 min, but changes in catch rate were not related to changes in ambient moonlight. In contrast, the volume of zooplankton collected was correlated with moonlight intensity. Dynamics of the ten dominant fish families were highly variable, but in most cases a large proportion of the larvae were caught on just a few nights. Taxonomic and size selectivities were apparently less severe in my study than in previous Australian studies, and the use of light-traps should be explored further. In Chapter Two, I outline the prediction that larvae of small, non-pelagic spawning fishes should more frequently be retained over reefs during development than fishes with other combinations of body size and egg type, and I describe my research testing this prediction. I made about 160 collections of fish larvae with a light-trap and plankton net at 1, 20, and 100 m from rocky shorelines. These collections yielded 27,265 larvae from about 50 families. Based on larval size frequencies, near-reef concentration gradients, and abundances offshore, I identified four families that can complete development over the reef but also have larvae dispersed offshore (Clupeidae, Engraulididae, Gerreidae, and Haemulidae). In addition, I identified seven families that primarily develop over reefs and have few or no larvae dispersed offshore (Tripterygiidae, Chaenopsidae, some Labrisomidae, Dactyloscopidae, some Gobiidae, Gobiesocidae, and Bythitidae). Adults of these seven families are mostly small, non-pelagic spawners. Larvae from four taxa of larger non-pelagic spawners (Ophioblennius, Labrisomus, Balistes, and Pomacentridae) did not appear to develop over reefs. These findings are in accord with the prediction I made. Chapter Three is a preliminary guide to identification of Gulf of California blennioid larvae. Although blennioid larvae are poorly known and few species have been described, they are well represented (ca. 20,000 larvae from five families) in my collections taken near reefs in the Gulf. Illustrations of 20 species, and brief descriptions of key characters for these and several additional species, are provided. More detailed taxonomic studies on Gulf blenniid, dactyloscopid, tripterygiid, labrisomid, and chaenopsid larvae are in progress.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectFishes -- Larvae.en_US
dc.subjectFishes -- Mexico -- California, Gulf of.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineEcology and Evolutionary Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairThomson, Donald A.en_US
dc.contributor.committeememberBrown, Jamesen_US
dc.contributor.committeememberBronstein, Judith L.en_US
dc.contributor.committeememberFlessa, Karlen_US
dc.contributor.committeememberHastings, Philipen_US
dc.contributor.committeememberStrauss, Richard E.en_US
dc.identifier.proquest9303314en_US
dc.identifier.oclc704284786en_US
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