Gonadal Maturation in the Cobia, Rachycentron canadum, from the Northcentral Gulf of Mexico

Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence of resting ovaries in July suggest two major spawning periods; however, monthly gonosomatic indices peaking in May, followed by a steady decline, do not support that finding. Ovaries were placed into undeveloped, early developing, mid-developing , or late developing categories based upon oocyte size-frequency distributions. Developing ovaries had two or three modes of oocytes larger than 30 pm. Batch fecundity was estimated to be 2.6x106 to 1.91x108 oocytes, depending on the size of fish/ovaries. The smallest female with oocytes exhibiting vitellogenesis was 834 mm FL. This fish was 2 years old based its otolith evaluation. The smallest male with an abundance of spermatozoa in its testes was 640 mm FL and 1 year old based on otolith evaluation; smaller males were not examined. Females larger than 840 mm FL had vitellogenic oocytes in March and April. A few fish still had vitellogenic oocytes in early October, but none did by late October. When Gilson’s fluid was used to assess ovarian tissue, the fresh weight of the tissue was reduced by 20% after being stored for 3 months. The diameter of oocytes shrunk about 25% in Gilson’s fluid which was 11% less than those fixed in formalin, embedded in paraffin, and sectioned. Tissue sections from specific individuals, each demonstrating a variety of different developmental stages, were similar regardless of whether they were obtained from the anterior, middle, or posterior portion of either ovary

Gonadal Maturation in the Cobia, Rachycentron canadum, from the Northcentral Gulf of Mexico

Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence of resting ovaries in July suggest two major spawning periods; however, monthly gonosomatic indices peaking in May, followed by a steady decline, do not support that finding. Ovaries were placed into undeveloped, early developing, mid-developing , or late developing categories based upon oocyte size-frequency distributions. Developing ovaries had two or three modes of oocytes larger than 30 pm. Batch fecundity was estimated to be 2.6x106 to 1.91x108 oocytes, depending on the size of fish/ovaries. The smallest female with oocytes exhibiting vitellogenesis was 834 mm FL. This fish was 2 years old based its otolith evaluation. The smallest male with an abundance of spermatozoa in its testes was 640 mm FL and 1 year old based on otolith evaluation; smaller males were not examined. Females larger than 840 mm FL had vitellogenic oocytes in March and April. A few fish still had vitellogenic oocytes in early October, but none did by late October. When Gilson’s fluid was used to assess ovarian tissue, the fresh weight of the tissue was reduced by 20% after being stored for 3 months. The diameter of oocytes shrunk about 25% in Gilson’s fluid which was 11% less than those fixed in formalin, embedded in paraffin, and sectioned. Tissue sections from specific individuals, each demonstrating a variety of different developmental stages, were similar regardless of whether they were obtained from the anterior, middle, or posterior portion of either ovary

Support Networks of Primary Caregivers Receiving Family Preservation Services: An Exploratory Study

Copyright 1994 Families International, Inc.The authors describe network characteristics and support resources from a clinical sample of 40 families. Data were obtained by family workers during the first two weeks of intervention. Case vignettes illustrate the multiple uses to which this information was put. Implications for future research and practice are discussed

Environmental organochlorines and semen quality: results of a pilot study.

There have been numerous studies that suggest that sperm concentrations (sperm counts) are declining in men. However, other studies suggest that sperm counts are not declining or may be increasing in some areas. Although there is disagreement on whether there is a downward temporal trend in sperm counts, the studies provide evidence that sperm counts vary by geographic location. It has been hypothesized that the geographic variation in sperm concentrations may be due to environmental exposures, lifestyle factors, or some unknown causes. To determine whether contemporary ambient levels of polychlorinated biphenyls (PCBs) and p,p-DDE are associated with altered semen quantity and quality, we selected a study population without specific exposure to PCBs or p,p-DDE. The present study presents the results from a pilot study on the relationship between serum PCBs and p,p-DDE and semen quality in 29 subjects recruited from the Massachusetts General Hospital Andrology Laboratory. Of the 29 subjects, 3 had sperm concentrations < 20 million/mL, 7 had < 50% motile sperm, 9 had < 4% normal morphology, and 6 were below normal in more than one semen parameter. The 18 subjects with normal spermatozoa concentration, motility, and morphology were used as comparison subjects. The mean (SE) concentration of the sum of PCBs and p,p-DDE was 242 ng/g lipids (34.0) and 354 ng/g lipids (120), respectively, for men with below normal motility as compared to 202 ng/g lipids (16.6) and 240 ng/g lipids (31.1), respectively, for the comparison subjects. The data showed general trends that were suggestive of an association between PCBs and p,p-DDE and abnormal motility, as well as with sperm concentration and morphology. A full-scale study is currently in progress

Reproductive Biology of Cobia, Rachycentron canadum, from Coastal Waters of the Southern United States

Reproductive biology of the cobia, Rachycentron canadum, is described from four coastal areas in the southern United States. Samples were obtained from recreational fishermen between December 1995 and November 1997 from the southeastern United States (Morehead City, NC, to Cape Canaveral, FL), the eastern Gulf of Mexico (Ft. Myers to Crystal River, FL), the north-central Gulf of Mexico (Destin, FL, to Chandeleur Islands, LA) and the western Gulf of Mexico (Port Aransas, TX). Histological evidence of spawning occurred from April through September in all areas. Some female cobia (17-32%) throughout the Gulf of Mexico had spent or regressed ovaries by July. Gonadosomatic index peaked between May and July throughout the region. Ovaries of females from all areas contained both postovulatory follicles (POF) and oocytes in final oocyte maturation (FOM) during all months of the reproductive season. Batch fecundity was calculated by using three different methods: oocytes \u3e700 pm were fixed in 1) Gilson\u27s fixative or 2) 10% neutral buffered formalin (NBF), and 3)oocytes undergoing FOM were sectioned for histological examination. Mean batch fecundity ranged from 377,000 +/- 64,500 to 1,980,500 +/- 1,598,500 eggs; there was no significant difference among methods. Batch fecundity calculated with the NBF method showed a positive relationship with fork length (P=0.021, r(2)=0.132) and ovary-free body weight (OFBW; P=0.016, r(2)=0.143). Relative batch fecundity was not significantly different among months during the spawning season and averaged 53.1 +/-9.4 eggs/g OFBW for the NBF method and 29.1 +/- 4.8 eggs/g OFBW for the FOM method. Although spawning frequencies were not significantly differ ent among areas (P=0.07), cobia from the southeastern United States and north-central Gulf of Mexico were estimated to spawn once every 5 days, whereas cobia from the western Gulf of Mexico were estimated to spawn once every 9 to 12 days

Reproductive Biology of Cobia, \u3ci\u3eRachycentron canadum\u3c/i\u3e, from Coastal Waters of the Southern United States

Reproductive biology of the cobia, Rachycentron canadum, is described from four coastal areas in the southern United States. Samples were obtained from recreational fishermen between December 1995 and November 1997 from the southeastern United States (Morehead City, NC, to Cape Canaveral, FL), the eastern Gulf of Mexico (Ft. Myers to Crystal River, FL), the north-central Gulf of Mexico (Destin, FL, to Chandeleur Islands, LA) and the western Gulf of Mexico (Port Aransas, TX). Histological evidence of spawning occurred from April through September in all areas. Some female cobia (17-32%) throughout the Gulf of Mexico had spent or regressed ovaries by July. Gonadosomatic index peaked between May and July throughout the region. Ovaries of females from all areas contained both postovulatory follicles (POF) and oocytes in final oocyte maturation (FOM) during all months of the reproductive season. Batch fecundity was calculated by using three different methods: oocytes \u3e700 μm were fixed in 1) Gilson’s fixative or 2) 10% neutral buffered formalin (NBF), and 3) oocytes undergoing FOM were sectioned for histological examination. Mean batch fecundity ranged from 377,000 ± 64,500 to 1,980,500 ± 1,598,500 eggs; there was no significant difference among methods. Batch fecundity calculated with the NBF method showed a positive relationship with fork length (P = 0.021, r2 = 0.132) and ovary-free body weight (OFBW; P = 0.016, r2 = 0.143). Relative batch fecundity was not significantly different among months during the spawning season and averaged 53.1 ± 9.4 eggs/g OFBW for the NBF method and 29.1 ± 4.8 eggs/g OFBW for the FOM method. Although spawning frequencies were not significantly different among areas (P = 0.07), cobia from the southeastern United States and north-central Gulf of Mexico were estimated to spawn once every 5 days, whereas cobia from the western Gulf of Mexico were estimated to spawn once every 9 to 12 days

Environmental Organochlorines and Semen Quality: Results of a Pilot Study

There have been numerous studies that suggest that sperm concentrations (sperm counts) are declining in men. However, other studies suggest that sperm counts are not declining or may be increasing in some areas. Although there is disagreement on whether there is a downward temporal trend in sperm counts, the studies provide evidence that sperm counts vary by geographic location. It has been hypothesized that the geographic variation in sperm concentrations may be due to environmental exposures, lifestyle factors, or some unknown causes. To determine whether contemporary ambient levels of polychlorinated biphenyls (PCBs) and p,p'-DDE are associated with altered semen quantity and quality, we selected a study population without specific exposure to PCBs or p,p'-DDE. The present study presents the results from a pilot study on the relationship between serum PCBs and p,p'-DDE and semen quality in 29 subjects recruited from the Massachusetts General Hospital Andrology Laboratory. Of the 29 subjects, 3 had sperm concentrations < 20 million/mL, 7 had < 50% motile sperm, 9 had < 4% normal morphology, and 6 were below normal in more than one semen parameter. The 18 subjects with normal spermatozoa concentration, motility, and morphology were used as comparison subjects. The mean (SE) concentration of the sum of PCBs and p,p'-DDE was 242 ng/g lipids (34.0) and 354 ng/g lipids (120), respectively, for men with below normal motility as compared to 202 ng/g lipids (16.6) and 240 ng/g lipids (31.1), respectively, for the comparison subjects. The data showed general trends that were suggestive of an association between PCBs and p,p'-DDE and abnormal motility, as well as with sperm concentration and morphology. A full-scale study is currently in progress

Geographic differences in semen quality of fertile U.S. males.

Although geographic variation in semen quality has been reported, this is the first study in the United States to compare semen quality among study centers using standardized methods and strict quality control. We evaluated semen specimens from partners of 512 pregnant women recruited through prenatal clinics in four U.S. cities during 1999-2001; 91% of men provided two specimens. Sperm concentration, semen volume, and motility were determined at the centers, and morphology was assessed at a central laboratory. Study protocols were identical across centers, and quality control was rigorously maintained. Sperm concentration was significantly lower in Columbia, Missouri, than in New York, New York; Minneapolis, Minnesota; and Los Angeles, California. Mean counts were 58.7, 102.9, 98.6, and 80.8 X 10(6)/mL (medians 53.5, 88.5, 81.8, and 64.8 X 10(6)/mL) in Missouri, New York, Minnesota, and California, respectively. The total number of motile sperm was also lower in Missouri than in other centers: 113, 196, 201, and 162 X 10(6) in Missouri, New York, Minnesota, and California, respectively. Semen volume and the percent morphologically normal sperm did not differ appreciably among centers. These between-center differences remained significant in multivariate models that controlled for abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease, and recent fever (all p-values < 0.01). Confounding factors and differences in study methods are unlikely to account for the lower semen quality seen in this mid-Missouri population. These data suggest that sperm concentration and motility may be reduced in semirural and agricultural areas relative to more urban and less agriculturally exposed areas

Genetic Susceptibility of Cultured Shrimp (\u3ci\u3ePenaeus vannamei\u3c/i\u3e) to Infectious Hypodermal and Hematopoietic Necrosis Virus and \u3ci\u3eBaculovirus penaei\u3c/i\u3e: Possible Relationship with Growth Status and Metabolic Gene Expression

Offspring of four crosses (I, II, III, and IV) of Penaeus vannamei from known high- and low-growth families were challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV) and Baculovirus penaei (BP) to compare their susceptibility to these viral agents and examine the genetic component involved in disease resistance or susceptibility. Family crosses were made using broodstock from five families developed by the U.S. Marine Shrimp Farming Program. The prevalence of IHHNV infection was highest in cross I and lowest in cross III. Cross I was developed using male and female broodstock from the low-growth family 1.6, and cross III was developed using a female from the high-growth family 1.3 and a male from the low-growth family 1.6. The prevalence of BP infection at Day 4 was highest (100%) in cross IV, which was developed using a female from the low-growth family 1.4 and a male from the high-growth family 1.5. The reciprocal cross, cross III, had the lowest (68%) prevalence at Day 4 postexposure. Both crosses I and II had 88% prevalence of infection at Day 4. Despite 100% prevalence of BP infection in cross IV at 4 days, animals from this cross and cross II exhibited high survival by Day 18 (85 and 77%). On the other hand, crosses I and III (with 88 and 68% prevalence at Day 4, respectively) showed low survival at Day 18 (19 and 24%). On the basis of prevalence of infection and mortality rates, it was concluded that the susceptibility to BP in penaeid shrimp is governed by the genetic background of the parental crosses. The random amplified polymorphic DNA polymorphisms for crosses I, II, III, and IV, were 43, 45, 53, and 51%, respectively, showing no clear relationship between IHHNV and BP prevalence of infection and levels of nuclear genetic diversity. Though the mtDNA haplotypes in offspring from the different crosses were the same, major differences were observed in both steady-state levels and patterns of expression of the mitochondrial 12s rRNA in offspring obtained at various early developmental stages from each of the four crosses. The possible relationship among disease susceptibility, growth status, and expression of mitochondrial 12s rRNA is discussed in the context of a complex nuclear-cytoplasmic genetic system involved in the regulation of gene expression