Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Gravid Female ◽  
Primary Source ◽  
Commercial Fishing ◽  
Natural Mortality ◽  
Ultrasonic Telemetry ◽  
Spawning Habitat ◽  
Arkansas River ◽  
Kaplan Meier ◽  
Commercial Harvest ◽  
Gravid Females

<em>Abstract</em>.—We assessed potential impacts of harvest and proposed channel modifications on the paddlefish <em>Polyodon spathula </em>fishery of Ozark Lake, Arkansas River, Arkansas. Ultrasonic telemetry was used to determine commercial and recreational exploitation rates, survival, spawning locations, and habitat use of gravid female paddlefish. Monthly searches were conducted for 40 tagged fish and we recorded 862 locations in Ozark Lake from January 2004 through December 2005. Adjacent reservoirs (i.e., Pool 13 and Lake Dardanelle) were tracked periodically, but interpool movement was not detected. Commercial fishing exploitation was determined at a mandatory check station and was estimated to be 30% during a 5-d special season. Annual recreational snag-fishing exploitation estimates were 8% (2004) and 3% (2005). Survival was different between years and was much lower the year (2004) with a commercial fishing season. Kaplan-Meier staggered-design survival estimates (±95% confidence interval [CI]) for 2004, 2005, and 2004 through 2005 were 0.60 ± 0.19, 0.92 ± 0.11, and 0.55 ± 0.18, respectively. With commercial and recreational harvests omitted from the analysis, the estimated 2-year survival rate was 0.91 ± 0.13 (±95% CI), which corresponds to 5% annual natural mortality. Gravid females migrated a median distance of 33 and 32 km in the spring of 2004 and 2005 and likely spawned in the tailwater of James W. Trimble Lock and Dam from late March to early April. Successful paddlefish reproduction was verified by capture of 23 prolarvae. Paddlefish selected tributary mouth habitat in all seasons (59% of locations). Tailwater and inundated creek channel habitats were selected in spring and summer, respectively. A navigation project to deepen the channel from 2.7 to 3.7 m will impact approximately 50% of the tailwater spawning habitat. Channel modifications (i.e., dredging and dike construction) near the mouth of the Mulberry River may disturb an important tributary mouth habitat for paddlefish where 55% of all locations were recorded. Our study identified biologically important habitats that need conservation and indicates that commercial harvest was the primary source of mortality for gravid female paddlefish in Ozark Lake.

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
21St Century ◽  
Time Lag ◽  
Management Tool ◽  
Commercial Fishing ◽  
Short Term ◽  
Arkansas River ◽  
Harvest Rate ◽  
The Mean ◽  
Illegal Activities ◽  
Gravid Females

<em>Abstract</em>.— Four special commercial fishing seasons (5–10 d) with mandatory check stations were used to closely monitor the harvest and exploitation of paddlefish Polyodon spathula in Ozark Lake and Pool 13 of the Arkansas River, Arkansas. The mean number of fishers (± SD) participating was 36 ± 25, and participation of statewide licensed fishers was high at 64% ± 18%. Average harvest (± SD) among seasons was 1,538 ± 652 fish and 866 ± 319 gravid females. The mean harvest rate (±SD) was 12 ± 6 fish/fisher-day effort. Exploitation estimates ranged between 19% and 40% during the 5-d seasons. Catch declined as the season progressed at Pool 13 and with a time lag at Ozark Lake. The short-term special seasons comprised 11–22% of the Arkansas statewide roe harvest for 2003, 2004, and 2006. The 5-d special season comprised 63% of the roe and 32% of the gravid females harvested for the 150-d Ozark Lake 2006–2007 season. A total of 27 citations were written for illegal activities, and bycatch mortality was a serious management concern at the 2006 Pool 13 season. Check stations provided a valuable management tool for accurately determining harvest and exploitation, and the brief special seasons allowed for controlled, monitored, and limited harvest. Illegal activities and large increases in the number of fishers entering the fishery were major threats to management for a sustainable roe fishery.

Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

2007 ◽  
Keyword(s):  
Gulf Of Mexico ◽  
Fork Length ◽  
Red Snapper ◽  
Minimum Size ◽  
Minimum Length ◽  
Commercial Fishing ◽  
Lutjanus Campechanus ◽  
Commercial Harvest ◽  
Length Regulation ◽  
The U.S

<em>Abstract.</em>—Red snapper <em>Lutjanus campechanus </em>were sampled from commercial landings from the Gulf of Mexico (GOM) off Louisiana from October 2001 to May 2004. Fork length (FL), eviscerated weight, otoliths (both sagittae), and sex determinations were taken from 2,900 specimens; FL was subsequently converted to total length (TL) with the equation TL = 1.073 (FL) + 3.56. Red snapper ages (<EM>N </EM>= 2,867) estimated from counts of opaque annuli in otoliths ranged from 1 to 14 years; however, the vast majority (97.7%) of these were ages 2 to 6 years and the modal age was 3 years. Total lengths among 2,897 specimens ranged from 278 to 940 mm, modal TL was 400 mm, and 98% of all specimens were less than 600 mm TL. We also investigated the fate of red snapper regulatory discards (individuals <381 mm [15 in] TL) during 16 trips on working commercial vessels; over two-thirds of 4,839 red snapper assigned among four discard fate categories (ranging from alive and vigorous to dead) were returned to the water either in moribund or dead condition. Among 399 potential discards retained for age and length analyses, 86% were between 12 and 15 in (305–381 mm) TL and 85% were 2 years of age. The minimum size regulation appears to do little to protect juvenile red snapper from commercial fishing mortality. Heavy red snapper mortality, which begins as bycatch mortality in shrimp trawls, continues as discard mortality at sub-legal lengths when they first recruit to the offshore fishing grounds, and persists as harvest mortality among the youngest legal year- and size-classes. If the minimum size limit is intended to provide a respite from such mortality, a reconsideration of the utility of the minimum length regulation in the commercial harvest of red snapper may be warranted.

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Mississippi River ◽  
First Year ◽  
State Agencies ◽  
Ohio River ◽  
Independent Data ◽  
Arkansas River ◽  
Commercial Harvest ◽  
Harvest Data ◽  
Sport Fisheries ◽  
Anthropogenic Alterations

<em>Abstract</em>.—Paddlefish <em>Polyodon spathula </em>have been intensively harvested in both sport and commercial fisheries. Recent harvests (2000–2006) were surveyed from state agencies and compared to historical harvests (1965– 1975). Seven major sport fisheries had recent annual harvests greater than 1,000 fish, and most large sport fisheries appeared to have sustainable harvests due to intensive management. Recent commercial harvest was greater than sport harvest across the species’ range. Most of the commercial harvest was from Arkansas, Kentucky, and Tennessee. Annual commercial harvest from the Ohio River increased from 6,000 to 196,000 kg from 1965–1975 to 2000–2006. Annual harvest remained substantial from the Arkansas River (37,000 kg), the lower Tennessee River (121,000 kg), and the Mississippi River (103,000 kg). Harvests of paddlefish (sport and commercial) compiled from the literature were highly variable and ranged between 0.01 and 5.06 fish/ ha and 0.04–43.43 kg/ha (median = 0.12 fish/ha, 1.73 kg/ha). Stock depression has been associated with a first-year harvest as low as 1.46 kg/ha, and harvests greater than 5 kg/ha were usually associated with overfishing or opening a previously closed fishery. Case histories from the Tennessee and Ohio River systems documented that paddlefish were susceptible to overharvest in lentic waters and river reservoirs, but the threat posed by commercial harvest from large rivers will remain unresolved until more fisheries-independent data becomes available. Anthropogenic alterations to habitat, overreliance on harvest data, and lack of fisheries-independent data limit our historical understanding of the degree of threat that harvest is to paddlefish populations.

Social context alters retreat- and nest-site selection in a globally invasive gecko, Hemidactylus frenatus

2019 ◽  
Vol 129 (2) ◽  
pp. 388-397
Author(s):  
Benjamin J Muller ◽  
Robin M Andrews ◽  
Lin Schwarzkopf ◽  
David A Pike
Keyword(s):  
Invasive Species ◽  
Site Selection ◽  
Nest Site ◽  
Gravid Female ◽  
Nest Site Selection ◽  
Invasion Success ◽  
Ceramic Tiles ◽  
Nest Sites ◽  
Gravid Females ◽  
Hemidactylus Frenatus

Abstract Microhabitat orientation and structure and the presence of conspecifics may strongly influence the choice of habitat. We studied how these variables influence retreat- and nest-site selection in gravid females of a globally successful invasive species, the Asian house gecko (Hemidactylus frenatus). When provided with various substrates (vertical and horizontal ceramic tiles, vertical and horizontal plywood tiles, horizontal bark over leaf litter, vertical bark over a log, and sand) gravid female geckos preferred to retreat to, and nest in, materials with crevices commonly found in urban habitats. When housed alone, gravid females most frequently retreated to vertical ceramic tile or wooden crevices, and 66.7% nested in vertical ceramic tiles. When housed with two other conspecifics, gravid females most frequently retreated to vertical ceramic tiles, but selected a wider range of nest sites. Overall, gravid geckos housed alone typically nested in the same substrates that they used as diurnal retreats; when housed in groups, however, females oviposited in locations different from those they selected as retreats. Thus, H. frenatus females use a wider range of substrates when conspecifics are present. Invasion success in this species might be driven, in part, by preferences for retreat and nest substrates that are common in human-dominated habitats.

scholarly journals First Report of the Root-Knot Nematode Meloidogyne arenaria on Cheeseweed Mallow (Malva parviflora) in the United States

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 296-296 ◽  
Author(s):  
N. Kokalis-Burelle ◽  
E. N. Rosskopf ◽  
J. Holzinger
Keyword(s):  
Mass Culture ◽  
Gravid Female ◽  
The United States ◽  
Egg Mass ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Malva Parviflora ◽  
Gravid Females ◽  
And Control ◽  
Esterase Phenotype

During a 2010 field trial for examining alternatives to methyl bromide soil fumigation for the production of field-grown cut flowers, weeds were collected for identification and evaluated for their potential as hosts for plant pathogenic nematodes. In one cut flower field located in Martin County, FL, six cheeseweed mallow (Malva parviflora L.) plants were collected that had root-galling typical of infection by a root-knot nematode (Meloidogyne spp.). Field collected plants were used for species identification of the weed and maintained in the greenhouse for seed production. Several gravid female nematodes were extracted from field collected mallow roots and individually identified as Meloidogyne arenaria based on their esterase phenotype (PhastSystem, GE Healthcare) (1). A single egg mass was then extracted from the field collected mallow roots and inoculated onto a tomato plant (Solanum lycopersicum, ‘Rutgers’) grown in steamed builders sand in the greenhouse. The single egg mass culture was increased for 8 weeks, until galling was sufficient to produce adequate nematode inoculum to complete Koch's postulates on the original mallow host. Ten mallow plants were inoculated with single egg masses originally isolated from mallow and increased on tomato. Ten additional plants were maintained in the greenhouse as uninoculated controls. Inoculated and control mallow plants were grown in the greenhouse for 8 weeks, after which the roots were evaluated for galling, and root-knot nematode J2 were extracted from roots and soil and counted. All inoculated plants produced galled roots and control plants did not. Gravid females were extracted from mallow roots and identified as M. arenaria based on esterase phenotype as previously described. Ten gravid females for each DNA extraction were collected from mallow roots and DNA was isolated with the PowerSoil DNA Isolation Kit (MO BIO Laboratories, Inc., Carlsbad, CA). Identification of M. arenaria was confirmed by using species-specific primers F5′-TCGAGGGCATCTAATAAAGG-3′ and R5′-GGGCTGAATAATCAAAGGAA-3′ (2) and F5′-TCGGCGATAGAGGTAAATGAC-3′ and R5′-TCGGCGATAGACACTACAACT-3′ (4), which produced single amplicon bands of the expected size of 420 and 950 bp, respectively. This weed species has been reported as a host for M. javanica in Algeria and as an experimental host in Egypt (3), but this report, to our knowledge, constitutes the first documentation of Malva parviflora as a natural host of M. arenaria. The importance of weeds as hosts for plant parasitic nematodes cannot be over emphasized. As growers, particularly in Florida and California, continue to lose tools for broad-spectrum pest control, the ability of nematodes to reproduce on uncontrolled weeds will become increasingly important. References: (1) J. A. Brito et al. Nematology 10:757, 2008. (2) K. Dong et al. Nematropica 31:273, 2001. (3) M. Quader et al. Australas. Plant Pathol. 30:357, 2001. (4) C. Zijlstra et al. Nematology 2:847, 2000.

scholarly journals Rheotaxis Response Based on Sexual Dimorphism in the Green Swordtail Fish, Xiphophorus hellerii

Biota ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 128-139
Author(s):  
Muhammad Irsyad Abiyusfi Ghafari ◽  
Vita Fitrianti
Keyword(s):  
Sexual Dimorphism ◽  
Gravid Female ◽  
Adult Males ◽  
Dioecious Species ◽  
Swordtail Fish ◽  
Xiphophorus Hellerii ◽  
Males And Females ◽  
Morphological Differences ◽  
Gravid Females ◽  
The Individual

Morphological distinctions between males and females of a species are referred to by sexual dimorphism. It may result from various selection pressures affecting either sex or both and may occur in any dioecious species, including Green Swordtail fish, which are sexually reproductive. This study examined the different rheotaxis responses of Xiphophorus hellerii based on different sexes and morphological features. We analyzed ten adult males, ten gravid females, and ten non-gravid females of Xiphophorus helleri collected down the river and transferred into the column. We counted the number of the individual that performed positive rheotaxis (+), negative rheotaxis (-), and indifference response (0). The result showed different rheotaxis responses shown by male, non-gravid female, and gravid female X. hellerii. The highest percentage of positive rheotaxis response (movement against the current) was shown by non-gravid female X. hellerii, reaching up to 89%. Morphological differences between male, non-gravid female, and gravid female X. hellerii appear to affect the orientation and ability of X. hellerii in giving response against current and certainly has an impact on their survival in nature.

scholarly journals Buckleyella ornata n. sp. (Nematoda: Philometridae) from the abdominal cavity of the talang queenfish Scomberoides commersonnianus (Perciformes: Carangidae) off the northern coast of Australia

2014 ◽  
Vol 51 (3) ◽  
pp. 230-235 ◽  
Author(s):  
F. Moravec ◽  
B. Diggles ◽  
L. Barnes ◽  
W. Macbeth
Keyword(s):  
Abdominal Cavity ◽  
Gravid Female ◽  
Nematode Species ◽  
The Body ◽  
Nominal Species ◽  
Northern Coast ◽  
Microscopical Examination ◽  
Electron Microscopical ◽  
Gravid Females ◽  
External Circle

AbstractA new nematode species, Buckleyella ornata n. sp. (Philometridae), is described from female specimens found in the abdominal cavity (mesenteries) of the talang queenfish Scomberoides commersonnianus Lacepède (Carangidae, Perciformes) caught in Darwin Harbour, northern Australia. Based on light and scanning electron microscopical examination, the new species mainly differs from the only other congeneric species B. buckleyi Rasheed, 1963 in having a markedly shorter oesophagus (2.04–2.75 mm long), by the absence of a cephalic mound around the mouth aperture, by the presence of four submedian cephalic papillae of the inner circle, and by a somewhat different arrangement of cuticular ornamentations on the body surface. Three protruding oesophageal teeth and large, dome-shaped cephalic papillae of the external circle present in the smallest gravid female of B. ornata are atrophied in larger conspecific gravid females. Buckleyella ornata is the first known nominal species of a philometrid parasitizing carangid fishes in Australian waters.

scholarly journals Root exudate chemical cues of an invasive plant modulate oviposition behavior and survivorship of a malaria mosquito vector

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Trizah K. Milugo ◽  
David P. Tchouassi ◽  
Reginald A. Kavishe ◽  
Rhoel R. Dinglasan ◽  
Baldwyn Torto
Keyword(s):  
Anopheles Gambiae ◽  
Survival Time ◽  
Root Exudate ◽  
Invasive Plant ◽  
Oviposition Behavior ◽  
Gravid Female ◽  
Larval Survival ◽  
Mosquito Vector ◽  
Treated Water ◽  
Gravid Females

AbstractGravid female Anopheles gambiae mosquitoes identify suitable oviposition sites through a repertoire of cues, but the influence of allelochemicals, especially root phytochemicals in modulating this behavior and impacting subsequent progeny bionomics remains unexplored. We addressed these questions in the malaria vector Anopheles gambiae and its invasive host plant Parthenium hysterophorus. Using chemical analysis combined with laboratory behavioral assays, we demonstrate that a blend of terpenes, namely α-pinene, α-phellandrene, β-phellandrene, 3-carene and (E)-caryophyllene emitted from P. hysterophorus root exudate treated-water attracted gravid females. However, fewer eggs (55%) hatched in this treatment than in control water (66%). The sesquiterpene lactone parthenin, identified in both the natural aquatic habitat harboring P. hysterophorus and root exudate-treated water was found to be responsible for the ovicidal effect. Moreover, larvae exposed to parthenin developed 2 to 3 days earlier but survived 4 to 5 days longer as adults (median larval survival time = 9 days (all replicates);11 to 12 days as adults) than the non-exposed control (median larval survival time = 11 days (reps 1 & 2), 12 days (rep 3); 6 to 7 days as adults). These results improve our understanding of the risk and benefits of oviposition site selection by gravid An. gambiae females and the role root exudate allelochemicals could play on anopheline bionomics, with potential implications in malaria transmission.

scholarly journals Density-dependent mating behaviors reduce male mating harassment in locusts

2021 ◽  
Vol 118 (42) ◽  
pp. e2104673118
Author(s):  
Koutaro Ould Maeno ◽  
Cyril Piou ◽  
Sidi Ould Ely ◽  
Sid’Ahmed Ould Mohamed ◽  
Mohamed El Hacen Jaavar ◽  
...  
Keyword(s):  
Gravid Female ◽  
Male Mating ◽  
Group Separation ◽  
Density Dependent ◽  
Gregarious Behavior ◽  
Open Ground ◽  
Pair Mating ◽  
Behavioral Group ◽  
Mating Behaviors ◽  
Gravid Females

Male mating harassment may occur when females and males do not have the same mating objectives. Communal animals need to manage the costs of male mating harassment. Here, we demonstrate how desert locusts in dense populations reduce such conflicts through behaviors. In transient populations (of solitarious morphology but gregarious behavior), we found that nongravid females occupied separate sites far from males and were not mating, whereas males aggregated on open ground (leks), waiting for gravid females to enter the lekking sites. Once a male mounted a gravid female, no other males attacked the pair; mating pairs were thereby protected during the vulnerable time of oviposition. In comparison, solitarious locusts displayed a balanced sex ratio in low-density populations, and females mated irrespective of their ovarian state. Our results indicate that the mating behaviors of desert locusts are density dependent and that sex-biased behavioral group separation may minimize the costs of male mating harassment and competition.

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