Evidence for sperm limitation in the blue crab, Callinectes sapidus

Reproductive success of female blue crabs may be limited by the amount of sperm received during the female\u27s single, lifetime mating. Sperm must be stored in seminal receptacles until eggs are produced and fertilized months to years after mating. Further, intense fishing pressure impacts male abundance, male size and population sex ratio, which affect ejaculate quantity. We measured temporal variation in seminal receptacle contents in relation to brood production for two stocks differing in both fishing pressure on males and latitudinal effects on reproductive season: Chesapeake Bay, Maryland and Virginia, experienced intensive fishing and relatively short reproductive season; and the Indian River Lagoon, Florida, experienced lower exploitation and longer reproductive season. Nearly all (\u3e98%) females were mated, and mating prevalence did not vary among sites during 1996. Seminal receptacle weight declined markedly for 2 mo following mating as seminal fluid disappeared to leave only spermatophores for long-term storage, which suggests that seminal fluid serves as a short-term sperm plug. Seminal receptacle weight in upper Chesapeake Bay declined by 31 % from 1992-1999, indicating that females received smaller ejaculates. In 1996, seminal receptacle contents were highest (3.75 g wet wt, 2.3 x 10(3) mug DNA, 1.2 x 10(9) sperm) in Florida, but were significantly lower by: 25% for weight and 50% for sperm number at the upper Chesapeake Bay site; and 30% for weight and 65% for sperm number at lower Chesapeake Bay sites. Generally, females receive 2-3 x 10(3) spermatophores and 10(8)-10(9) sperm cells for a full ejaculate, whereas females produce ca. 3 x 10(6) eggs per brood. Chesapeake Bay females appear to live about 3.5 yr, producing 1-3 broods (up to 9 x 10(6) eggs) per year and up to 6-7 broods (2.1 x 10(7) eggs) per lifetime. In contrast, Florida crabs produced up to 6-7 broods (2.1 X 101 eggs) per year. and up to 18 broods (5.4 x 10(7) eggs) per lifetime. In Florida, last broods produced by lab-held females were often infertile, indicating that females became sperm limited at the end of their lifetime. Experiments showed that male mating history affected female reproductive success, with females mated late in a sequence having only one third the brood hatching success of females mated early in the sequence. Sperm : egg ratios were estimated at 100: 1 to 400:1 for the first brood but only about 20:1 or 30:1 for maximum lifetime broods over 2 seasons, suggesting that about 67 x 10(6) sperm are used per brood of 3 x 10(6) eggs. A model of brood production and sperm depletion in blue crabs indicates that sperm limitation may be common in Florida as females age, and in Chesapeake Bay as a result of fishery-induced reductions in initial quantities of sperm transferred at mating

2011 Wild Blueberry Project Reports

The 2011 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Mechanisms through which wild blueberries affect functional characteristics of the arterial wall related to endothelial dysfunction in Spontaneously Hypertensive Rats 2. Do wild blueberries affect high blood lipids, high blood glucose and obesity as related to the Metabolic Syndrome? 3. Control tactics for blueberry pest insects, 2011 4. IPM strategies, 2011 5. Biology and ecology of pest insects, 2011 6. Biology and ecology of beneficial insects, 2011 7. Pesticide residues on lowbush blueberry, 2011 8. Maine wild blueberry –mummy berry research and extension 9. Valdensinia leaf spot – Education, control and research – 2011 10. Effect of soil pH on nutrient uptake 11. Evaluation of several growth regulators for stimulating lowbush blueberry rhizome production 12. Evaluation of the effects of Gypsum (CaSO4) on wild blueberry fruit Ca concentration 13. Fall application of tribenuron methyl for bunchberry control in wild blueberries, 2009-2011 – effects of fall versus spring pruning on cover and yield in the crop year (final report) 14. Wild Blueberry Extension Education Program in 2011 INPUT SYSTEMS STUDY: 15. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study – experimental design 16. The effects of different agronomic practices on the composition and quality of wild blueberries 17. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, blueberry quality from the first harvest year 18. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 19. Abundance of insect pest species and natural enemies in lowbush blueberry fields maintained under different management practices 20. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, disease management results 21. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, weed management results 22. Systems approach to improving sustainability of wild blueberry production, Year 1 of a four-year study, preliminary soil health and chemistry results 23. Management effects on the phosphorus chemistry of wild blueberry barrens soil 24. Systems approach to improving the sustainability of wild blueberry production, preliminary economic comparison 2010-2011 25. Transition to organic production Year 2: Evaluation of gypsum and bone char 26. The effect of field management, forest edge composition, and field location on insect-mediated ecosystem services (scavenging/predation) (ancillary study) 27. Pre-emergent combinations of herbicides for weed control in wild blueberry fields (ancillary study) 28. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, year 1 (ancillary study) 29. Effects of compost and mulch on soil health and soil nutrient dynamics in wild blueberry (ancillary study

2012 Wild Blueberry Project Reports

The 2012 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Do wild blueberries alleviate risk factors related to the Metabolic Syndrome? 2. Development of effective intervention measures to maintain and improve food safety for wild blueberries 3. Control tactics for blueberry pest insects, 2012 4. Development and implementation of a wild blueberry thrips IPM program, 2012 5. IPM 6. Biology of blueberry and pest insects, 2012 7. Biology of beneficial insects and blueberry pollination, 2012 8. Pesticide residues on lowbush blueberry, 2012 9. Maine wild blueberry –mummy berry research and extension 10. Efficacy of Apogee growth regulator for stimulating rhizome growth into bare spots in wild blueberry fields 11. Velpar by Matrix pre and post-emergence applications - demonstration plots 12. Wild blueberry Extension Education Program in 2012 INPUT SYSTEMS STUDY: 13. Systems approach to improving the sustainability of wild blueberry production, Year Three of a four-year study – experimental design 14. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 15. Abundance of insect pest species and natural enemies in lowbush blueberry fields maintained under different management practices 16. Input Systems Study: Systems approach to improving the sustainability of wild blueberry production, Year 3 of a four-year study, disease management results 17. Plant productivity, Year Three of a four-year study 18. Systems approach to improving the sustainability of wild blueberry production, Year Three of a four-year study, weed management results 19. Effects of organic and conventional management systems on the phosphorus solubility of lowbush blueberry barren soils 20. Systems approach to improving sustainability of wild blueberry production – soil health and chemistry measures 21. Evaluation of fungicides for control of mummy berry disease (ancillary study) 22. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, Year Two of a four-year study (ancillary study) 23. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2012 results from the 2011 trial (ancillary study) 24. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2012 trial (ancillary study) 25. Evaluation of herbicides for control of fineleaf sheep fescue for grass control in wild blueberries (ancillary study) 26. Pre-emergence application timing and rate of Alion and Sandea in combination with Velpar or Sinbar on weed control and injury to wild blueberry (ancillary study) 27. Compost and mulch effects on soil health and nutrient dynamics in wild blueberry (ancillary study

2013 Wild Blueberry Project Reports

The 2013 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Development of effective intervention measures to maintain and improve food safety for wild blueberries 2. Do wild blueberries alleviate risk factors related to the Metabolic Syndrome? 3. Wild Blueberry consumption and exercise-induced Oxidative Stress: Inflammatory Response and DNA damage 4. Control tactics for blueberry pest insects, 2013 5. Pesticide residues on wild blueberry, 2013 6. Biology of pest insects and IPM, 2013 7. Biology of blueberry, beneficial insects, and blueberry pollination 8. Biology of spotted wing drosophila, 2013 9. Maine wild blueberry –mummy berry research and extension 10. Evaluation of fungicides for control of mummy berry on lowbush blueberry (2013) 11. Wild blueberry Extension Education Program in 2013 INPUT SYSTEMS STUDY: 12. Systems approach to improving the sustainability of wild blueberry production, Year Four of a four-year study – experimental design 13. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 14. Agronomic input effects on sensory quality and chemical composition of wild Maine blueberries 15. Systems approach to improving the sustainability of wild blueberry production, Year four of a four-year study – reports from Frank Drummond 16. Systems approach to improving the sustainability of wild blueberry production, Year 4 of a four-year study, disease management results 17. Systems approach to improving the sustainability of wild blueberry production, Year Four of a four-year study, weed management results 18. Phosphorus and organic matter interactions on short-range ordered minerals in acidic barren soils 19. Systems approach to improving the sustainability of wild blueberry production, preliminary economic comparison for 2012-13 20. Ancillary projects in disease research (ancillary study) 21. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, Year Three of a four-year study (ancillary study) 22. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2013 results from the 2012 trial (ancillary study) 23. Evaluation of herbicides for 2012 prune year control of fineleaf sheep fescue in wild blueberries – 2013 crop year results (ancillary study) 24. 2012 pre-emergence application timing and rate of Alion and Sandea in combination with Velpar or Sinbar – 2013 yields (ancillary study) 25. Pre-emergence Sinbar combinations for weed control in a non-crop wild blueberry field – 2012-2014 (ancillary study) 26. Evaluation of three pre-emergence herbicides alone and in combination with Velpar or Sinbar for effects on wild blueberry productivity and weed control (ancillary study) 27. Post-harvest control of red sorrel in a non-crop blueberry field, 2012-2014 (ancillary study) 28. Compost and mulch effects on soil health and nutrient dynamics in wild blueberry (ancillary study) 29. Evaluation of conventional and organic fertilizers on blueberry growth and yield (ancillary study

Concurrent Signals and Behavioral Plasticity in Blue Crab (Callinectes sapidus Rathbun) Courtship

Volume: 197Start Page: 63End Page: 7