Diet and egg production of the copepod Acartia tonsa in Florida Bay. II. Role of the nutritional environment

2000 ◽  
Vol 137 (1) ◽  
pp. 111-121 ◽  
Author(s):  
G. S. Kleppel ◽  
S. E. Hazzard
Keyword(s):  
Egg Production ◽  
Florida Bay ◽  
Acartia Tonsa ◽  
Nutritional Environment

Egg Production of the Copepod Acartia tonsa in Florida Bay during Summer. 1. The Roles of Food Environment and Diet

Estuaries ◽  
1998 ◽  
Vol 21 (2) ◽  
pp. 328 ◽  
Author(s):  
G. S. Kleppel ◽  
Carol A. Burkart ◽  
Lee Houchin ◽  
Carmelo Tomas
Keyword(s):  
Food Environment ◽  
Egg Production ◽  
Florida Bay ◽  
Acartia Tonsa

THE ROLE OF SEA-LEVEL RISE AND STORMS IN FORMATION AND RESILIENCE OF FLORIDA BAY ISLANDS, EVERGLADES NATIONAL PARK

2019 ◽  
Author(s):  
G. Lynn Wingard ◽  
◽  
Miriam C. Jones ◽  
Sarah E. Bergstresser ◽  
Bethany L. Stackhouse ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
National Park ◽  
Florida Bay ◽  
Everglades National Park ◽  
Bay Islands

Effects of adult stocking density on egg production and viability in cultures of the calanoid copepod Acartia tonsa (Dana)

2007 ◽  
Vol 38 (7) ◽  
pp. 764-772 ◽  
Author(s):  
Per M Jepsen ◽  
Nikolaj Andersen ◽  
Thue Holm ◽  
Anders T Jørgensen ◽  
Jonas K Højgaard ◽  
...  
Keyword(s):  
Egg Production ◽  
Calanoid Copepod ◽  
Stocking Density ◽  
Acartia Tonsa

scholarly journals DOMINANCE AND EPISTASIS IN HETEROSIS OF WHITE LEGHORN STRAIN CROSSES

1987 ◽  
Vol 67 (3) ◽  
pp. 663-680 ◽  
Author(s):  
R. W. FAIRFULL ◽  
R. S. GOWE ◽  
J. NAGAI
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Significant Contribution ◽  
Production Traits ◽  
White Leghorn ◽  
Cross Combination ◽  
Commercial Strain ◽  
Better Than

Four unrelated pure strains of White Leghorns including a grandparent strain from industry and 12 two-strain, 24 three-strain, 24 four-strain and 12 F2 strain crosses produced contemporaneously were used to examine the role of dominance and epistasis in heterosis. A control strain and a commercial strain were also included. For egg weight, the heterosis observed closely approximated that expected due to dominance alone. For sexual maturity and body weight, dominance was the major component of heterosis, but epistasis made a significant contribution — additive by additive (A × A) genetic effects for sexual maturity and 140-d body weight, and parental epistasis for mature body weight. Both dominance and epistasis played a significant role in heterosis for egg production traits. A × A, dominance by dominance (D × D) and additive by dominance (A × D) epistasis were all important for hen-housed egg production and hen-housed egg yield. For hen-day rate of egg production, A × A epistasis was significant only early in the laying year (to 273 d), A × D and D × D were significant to 385 d and in the full year (to 497 d); however, none (A × A, A × D and D × D) was significant near the end of lay (386–497 d). Overall heterosis estimates for full year egg production measured as hen-housed egg production to 497 d or hen-day rate from housing to 497 d clearly showed that on average two-strain crosses were superior to three-strain crosses which were superior to four-strain crosses which in turn exceeded the F2 crosses. Nevertheless, several three-strain crosses had performance for egg production that was equal to or better than the two-strain cross with the highest egg production. Thus, in commerce, where the level of egg production is of great economic importance, the testing and use of a specific three-way cross combination will usually result in a better commercial product. Key words: Heterosis, egg production genetics, epistasis, stocking rate, strain cross, White Leghorn

scholarly journals Association of polymorphisms in the promoter region of turkey prolactin with egg performance

Genetika ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 591-599 ◽  
Author(s):  
Mehrangiz Fathi ◽  
Ghorban Elyasi-Zarringhobaie
Keyword(s):  
Promoter Region ◽  
Egg Production ◽  
Gene Promoter ◽  
Reproductive Traits ◽  
Egg Mass ◽  
Breeding Center ◽  
Egg Performance ◽  
East Azerbaijan ◽  
Prolactin Promoter

The induction and regulation of broodiness is of the most important role of prolactin in avian species. In this study, the association between prolactin promoter region alleles and reproductive traits in Fars native turkey was investigated. These traits consisted of mean egg weight (MEW), number of egg (EN) and egg mass, during the first laying period. In total, 115 laying turkeys, randomly selected from the flock of the Breeding Center for Fars Native turkey, and DNA was purificated from blood samples, 231 bp of prolactin promoter region was amplified and Genotype of Samples was determinate by PCR-SSCP technique were genotyped. Two alleles D and I were identified. Based on the results obtained, the frequency of D and I alleles were 0.67 and 0.33, respectively. Frequencies of DD, II and ID genotypes were 0.385, 0.044 and 0.571, respectively. The association analysis between the polymorphism PRL gene promoter region and egg performance was carried out. Significant relationship was found between genotypes with egg production (P<0.01). Individuals with II genotype produced higher egg production than DD and ID genotype. The results of current study showed that using information of genes related to egg production could be used to improve the performance of native turkey of East Azerbaijan province.

Copulation and Egg-Production in Rhodnius Prolixus: the Role of the Spermathecae

1965 ◽  
Vol 42 (3) ◽  
pp. 373-378
Author(s):  
K. G. DAVEY
Keyword(s):  
Egg Production ◽  
Rhodnius Prolixus ◽  
Seminal Vesicles ◽  
Primary Stimulus ◽  
Accessory Glands ◽  
Normal Males ◽  
Mated Female

1. Mated females of Rhodnius prolixus lay eggs at approximately twice the rate of unmated females. 2. Males which have had their seminal vesicles or opaque accessory glands removed produce spermatophores at mating, but no spermatozoa appear in the spermathecae of the females. The females involved in such matings do not exhibit an increase in egg-production. 3. When females lacking their spermathecae are mated to normal males, the increase in egg production which follows normal matings does not materialize. 4. Implanting spermathecae from mated females into virgin females increases the egg-production of the host. Implanting spermathecae from virgin females or seminal vesicles or transparent accessory glands from males has no effect on the egg-production of the donor. 5. It is tentatively concluded that a blood-borne factor from the spermathecae containing spermatozoa is the primary stimulus to increased egg production in a mated female.

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