The invasive macroalgal species Avrainvillea sp. and native species Halimeda kanaloana form expan... more The invasive macroalgal species Avrainvillea sp. and native species Halimeda kanaloana form expansive meadows that extend to depths of 80 m or more in the waters off of O‘ahu and Maui, respectively. Despite their wide depth distribution, comparatively little is known about the biota associated with these macroalgal species. Our primary goals were to provide baseline information on the fish fauna associated with these deep-water macroalgal meadows and to compare the abundance and diversity of fishes between the meadow interior and sandy perimeters. Because both species form structurally complex three-dimensional canopies, we hypothesized that they would support a greater abundance and diversity of fishes when compared to surrounding sandy areas. We surveyed the fish fauna associated with these meadows using visual surveys and collections made with clove-oil anesthetic. Using these techniques, we recorded a total of 49 species from 25 families for H. kanaloana meadows and surrounding ...
Data-limited fisheries benefit from using life-history traits as biological indicators of targete... more Data-limited fisheries benefit from using life-history traits as biological indicators of targeted stocks. We used histology-based reproductive analyses to estimate size at maturity, per capita egg production, and the number and biomass of immature individuals in the catch for three common coral reef fishes in Fiji market surveys during 2010–2019. We studied Lutjanus gibbus (Forsskål, 1775), Parupeneus indicus (Shaw, 1803), and Chlorurus microrhinos (Bleeker, 1854), which represent three families: Lutjanidae, Mullidae, and Scaridae, respectively. Fork length comprising 50% mature individuals for females of L. gibbus was 22.7 cm, that of P. indicus was 25.9 cm, attaining 38.0 cm for C. microrhinos. Females were rare or absent in the largest size classes of all three species. Immature fish represented up to 50% by number and 41% by biomass of the catch in market surveys, with P. indicus having the greatest immature number (8%‒50%) and biomass (6%‒41%), followed by C. microrhinos (20%‒...
This work is dedicated to my parents, John and Linda Langston. My success in graduate school was ... more This work is dedicated to my parents, John and Linda Langston. My success in graduate school was due largely to their encouragement, some hard work on my part, and also a good deal of luck. The completion of my degree illustrates the axiom: "Even a blind hog gets an acorn some of the time." IV ACKNOWLEDGMENTS I would like to thank my advisor David Greenfield for his advice and encouragement throughout my graduate student career. He has taught me a great deal about ichthyology. More importantly, he has taught me to enjoy my research. I would also like to thank my other committee members, George Losey, Chris Kelley, Tim Tricas, Bruce Mundy, and Cindy Hunter for their guidance and review of this dissertation. In particular, Bruce Mundy revised numerous drafts of this dissertation and greatly improved the accuracy and clarity of the final draft. Several individuals and institutions loaned or gave specimens for examination of gonads:
The labrid fish Cymolutes praetextatus, previously known from East Africa to the Society Islands ... more The labrid fish Cymolutes praetextatus, previously known from East Africa to the Society Islands but not east of the Marshall Islands in the North Pacific, is reported from the Hawaiian Islands from two specimens collected in 18 m and an underwater photograph taken in 27 m. One of the color descriptions by Jordan and Evermann in 1905 in their species account of C. lecluse indicates that they had a specimen of praetextatus.
ABSTRACT We herein evaluate several reproductive metrics of Hawaiian Archipelagic populations of ... more ABSTRACT We herein evaluate several reproductive metrics of Hawaiian Archipelagic populations of the bluespine unicornfish (Naso unicornis), an economically and ecologically important, broadly distributed tropical Pacific reef fish, based on multi-year, fishery-dependent and fishery-independent collections. Sex-specific spawning seasonality was characterized for fish collected mostly from Oahu (Main Hawaiian Islands, MHI) using a gonadosomatic index. Histological slides preparations were used to score gonad developmental phase and to classify individuals of either sex as immature or mature. Sex-specific median body lengths at maturity (L50) were estimated by logistic fits of proportion mature versus length class. Spawning was highly seasonal in Hawaii, with a single brief (May–June) peak spawning period. Proportionate gonad-to-body weight values were relatively low, averaging only about 0.1 % and 0.6 % across all months of year and 0.16 % and 1.03 % during May–June for males and females, respectively. Median lengths at sexual maturity differed between the sexes. L50 values for fish collected throughout all months of year were 30.1 ± 0.5 (standard error) cm Fork Length (FL) for males and 35.5 ± 0.7 cm FL for females. Spawning seasonality and L50 estimates for bluespine unicornfish in Hawaii suggest that the species spawns several months earlier in the calendar year and matures at larger body lengths in Hawaii versus Guam, the Northern Mariana Islands, and Pohnpei in the Federated States of Micronesia. Estimated lengths at sexual maturity are compared to the minimum length (14 inches or 35.6 cm FL) mandated for this species in Hawaii: median size at maturity occurs at a length appreciably less than (males) or approximately equal to (females) minimum legal size. A likely disproportionately large contribution of old females to population replenishment is discussed relative to the minimum size limit.
We present length-weight relations (LWR) and use rapid, low-cost histological methods to describe... more We present length-weight relations (LWR) and use rapid, low-cost histological methods to describe the reproductive biology of three reef fi shes from a remote area in Papua New Guinea: the striped monocle bream, Scolopsis lineata Quoy et Gaimard, 1824; the Indian goatfi sh, Parupeneus indicus (Shaw, 1803); and the blackbelly triggerfi sh, Rhinecanthus verrucosus (Linnaeus, 1758). The LWR for Scolopsis lineata is W = 0.0191FL 3.02. Male L 50 is 11.2 and female L 50 is 13.5 cm FL. Overall sex ratio is female biased; however, for mature individuals, females dominate size-classes from 13 through 15 cm and males dominate smaller and larger size classes. This species is a batch-spawning, protogynous hermaphrodite. The LWR for Parupeneus indicus is W = 0.00904FL 3.25. Male L m is 14.7 and female L 50 is 18.4 cm FL. Overall sex ratio is 1 : 1; however, for mature individuals, females dominate size-classes from 17 through 22 cm and males dominate smaller and larger size classes. This species is a batch-spawning gonochore. BF = 4.62FL 2.95. The LWR for Rhinecanthus verrucosus is W = 0.0257TL 2.97. Male L 50 is 13.0 and female L 50 is 14.1 cm TL. Overall sex ratio is female biased; however, mature individuals are male biased ≥ 16.1 cm TL and, effectively, exclusively male ≥ 17.6 cm. This species is a batch-spawning gonochore. BF = 3.35 • 10-19 TL 19.4 .
The invasive macroalgal species Avrainvillea sp. and native species Halimeda kanaloana form expan... more The invasive macroalgal species Avrainvillea sp. and native species Halimeda kanaloana form expansive meadows that extend to depths of 80 m or more in the waters off of O‘ahu and Maui, respectively. Despite their wide depth distribution, comparatively little is known about the biota associated with these macroalgal species. Our primary goals were to provide baseline information on the fish fauna associated with these deep-water macroalgal meadows and to compare the abundance and diversity of fishes between the meadow interior and sandy perimeters. Because both species form structurally complex three-dimensional canopies, we hypothesized that they would support a greater abundance and diversity of fishes when compared to surrounding sandy areas. We surveyed the fish fauna associated with these meadows using visual surveys and collections made with clove-oil anesthetic. Using these techniques, we recorded a total of 49 species from 25 families for H. kanaloana meadows and surrounding ...
Data-limited fisheries benefit from using life-history traits as biological indicators of targete... more Data-limited fisheries benefit from using life-history traits as biological indicators of targeted stocks. We used histology-based reproductive analyses to estimate size at maturity, per capita egg production, and the number and biomass of immature individuals in the catch for three common coral reef fishes in Fiji market surveys during 2010–2019. We studied Lutjanus gibbus (Forsskål, 1775), Parupeneus indicus (Shaw, 1803), and Chlorurus microrhinos (Bleeker, 1854), which represent three families: Lutjanidae, Mullidae, and Scaridae, respectively. Fork length comprising 50% mature individuals for females of L. gibbus was 22.7 cm, that of P. indicus was 25.9 cm, attaining 38.0 cm for C. microrhinos. Females were rare or absent in the largest size classes of all three species. Immature fish represented up to 50% by number and 41% by biomass of the catch in market surveys, with P. indicus having the greatest immature number (8%‒50%) and biomass (6%‒41%), followed by C. microrhinos (20%‒...
This work is dedicated to my parents, John and Linda Langston. My success in graduate school was ... more This work is dedicated to my parents, John and Linda Langston. My success in graduate school was due largely to their encouragement, some hard work on my part, and also a good deal of luck. The completion of my degree illustrates the axiom: "Even a blind hog gets an acorn some of the time." IV ACKNOWLEDGMENTS I would like to thank my advisor David Greenfield for his advice and encouragement throughout my graduate student career. He has taught me a great deal about ichthyology. More importantly, he has taught me to enjoy my research. I would also like to thank my other committee members, George Losey, Chris Kelley, Tim Tricas, Bruce Mundy, and Cindy Hunter for their guidance and review of this dissertation. In particular, Bruce Mundy revised numerous drafts of this dissertation and greatly improved the accuracy and clarity of the final draft. Several individuals and institutions loaned or gave specimens for examination of gonads:
The labrid fish Cymolutes praetextatus, previously known from East Africa to the Society Islands ... more The labrid fish Cymolutes praetextatus, previously known from East Africa to the Society Islands but not east of the Marshall Islands in the North Pacific, is reported from the Hawaiian Islands from two specimens collected in 18 m and an underwater photograph taken in 27 m. One of the color descriptions by Jordan and Evermann in 1905 in their species account of C. lecluse indicates that they had a specimen of praetextatus.
ABSTRACT We herein evaluate several reproductive metrics of Hawaiian Archipelagic populations of ... more ABSTRACT We herein evaluate several reproductive metrics of Hawaiian Archipelagic populations of the bluespine unicornfish (Naso unicornis), an economically and ecologically important, broadly distributed tropical Pacific reef fish, based on multi-year, fishery-dependent and fishery-independent collections. Sex-specific spawning seasonality was characterized for fish collected mostly from Oahu (Main Hawaiian Islands, MHI) using a gonadosomatic index. Histological slides preparations were used to score gonad developmental phase and to classify individuals of either sex as immature or mature. Sex-specific median body lengths at maturity (L50) were estimated by logistic fits of proportion mature versus length class. Spawning was highly seasonal in Hawaii, with a single brief (May–June) peak spawning period. Proportionate gonad-to-body weight values were relatively low, averaging only about 0.1 % and 0.6 % across all months of year and 0.16 % and 1.03 % during May–June for males and females, respectively. Median lengths at sexual maturity differed between the sexes. L50 values for fish collected throughout all months of year were 30.1 ± 0.5 (standard error) cm Fork Length (FL) for males and 35.5 ± 0.7 cm FL for females. Spawning seasonality and L50 estimates for bluespine unicornfish in Hawaii suggest that the species spawns several months earlier in the calendar year and matures at larger body lengths in Hawaii versus Guam, the Northern Mariana Islands, and Pohnpei in the Federated States of Micronesia. Estimated lengths at sexual maturity are compared to the minimum length (14 inches or 35.6 cm FL) mandated for this species in Hawaii: median size at maturity occurs at a length appreciably less than (males) or approximately equal to (females) minimum legal size. A likely disproportionately large contribution of old females to population replenishment is discussed relative to the minimum size limit.
We present length-weight relations (LWR) and use rapid, low-cost histological methods to describe... more We present length-weight relations (LWR) and use rapid, low-cost histological methods to describe the reproductive biology of three reef fi shes from a remote area in Papua New Guinea: the striped monocle bream, Scolopsis lineata Quoy et Gaimard, 1824; the Indian goatfi sh, Parupeneus indicus (Shaw, 1803); and the blackbelly triggerfi sh, Rhinecanthus verrucosus (Linnaeus, 1758). The LWR for Scolopsis lineata is W = 0.0191FL 3.02. Male L 50 is 11.2 and female L 50 is 13.5 cm FL. Overall sex ratio is female biased; however, for mature individuals, females dominate size-classes from 13 through 15 cm and males dominate smaller and larger size classes. This species is a batch-spawning, protogynous hermaphrodite. The LWR for Parupeneus indicus is W = 0.00904FL 3.25. Male L m is 14.7 and female L 50 is 18.4 cm FL. Overall sex ratio is 1 : 1; however, for mature individuals, females dominate size-classes from 17 through 22 cm and males dominate smaller and larger size classes. This species is a batch-spawning gonochore. BF = 4.62FL 2.95. The LWR for Rhinecanthus verrucosus is W = 0.0257TL 2.97. Male L 50 is 13.0 and female L 50 is 14.1 cm TL. Overall sex ratio is female biased; however, mature individuals are male biased ≥ 16.1 cm TL and, effectively, exclusively male ≥ 17.6 cm. This species is a batch-spawning gonochore. BF = 3.35 • 10-19 TL 19.4 .
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