scholarly journals Population structure and reproductive biology of Metamysidopsis neritica (Crustacea: Mysidacea) in a sand beach in south Brazil

2008 ◽  
Vol 25 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Patrícia Calil ◽  
Carlos A. Borzone
Keyword(s):  
Population Structure ◽  
Reproductive Biology ◽  
Direct Relationship ◽  
Surf Zone ◽  
Population Characteristics ◽  
Egg Volume ◽  
Sand Beach ◽  
The World ◽  
Egg Number ◽  
South Brazil

Mysidacea are common sublittoral crustaceans that inhabit all coasts in the world. In this study, the population characteristics and the reproductive biology of Metamysidopsis neritica Bond-Buckup & Tavares, 1992 were studied in the surf zone of a south Brazilian beach (Atami). Mysids were sampled at monthly intervals from August, 1999 to July, 2000 (total of 29,490 individuals). Individuals were classified into six population categories. The highest abundance occurred in May (8,665) and August (6,415), and lowest in September (336) and December (368). Three main generations were identified, namely the summer, fall and winter generations. The winter generation was the longest (four to five months). The fall generation lasted four months, and the summer one extended from three to four months. Ovigerous females occurred throughout the year, with a greater proportion in July. The number of eggs or larvae varied from one to 16. Weak associations were found between female length and egg number, egg volume, and the number of larvae with and without eyes. Egg volume increased during the coldest season, whereas the smallest values were recorded during summer. These results suggest a possible direct relationship between egg volume and generation longevity.

scholarly journals Population Structure and Reproductive Biology of the Endangered Crab Deiratonotus japonicus (Brachyura, Camptandriidae) Surveyed for Nine Years in the Kita River, Japan

2020 ◽  
Vol 8 (11) ◽  
pp. 921
Author(s):  
Il-Kweun Oh ◽  
Seung-Woo Lee
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Carapace Width ◽  
River Mouth ◽  
Sampling Period ◽  
Sampling Station ◽  
Egg Number ◽  
Kanagawa Prefecture ◽  
The Mean

Deiratonotus japonicus (D. japonicus) is known as a near-threatened species, because of the changing conditions of its habitat. This species resides in isolated locations and in upstream, brackish waters from Kanagawa Prefecture to Okinawa Prefecture in Japan. In this study, we investigated the population structure and reproductive biology of D. japonicus in the Kita River, Japan. The distribution, sex ratio, breeding season, and fecundity were assessed at bimonthly intervals during spring low-tide periods from May 2001 to November 2008 and from November 2014 to January 2016 for approximately nine years. A total of 3525 crabs were collected during the sampling period: 1806 (51.2%) males, 1240 (35.2%) non-ovigerous females, and 479 (13.6%) ovigerous females. The overall sex ratio (1:0.95) did not differ significantly from the expected 1:1 ratio. The mean maximum density was 26.1 and 36.5 indiv./m2 for the first and second sampling periods, respectively, in the sampling station 5.2 km from the Kita River mouth, and all individuals were typically found approximately 4.4–6.8 km (13.2 ± 7.8 indiv./m2) from the Kita River mouth. Carapace width (CW) ranged from 2.6 to 13.5 mm in males and from 2.8 to 13.4 mm in females and was significantly different between the two sexes (p < 0.05). Ovigerous females were found almost throughout the entire sampling period, with breeding peaks between July and September. The smallest ovigerous female had a CW of 3.9 mm. The seasonal frequency distribution suggested the continuous recruitment of young juveniles (CW < 3.9 mm) throughout the year, with peaks from September to November. The mean fecundity was 1008.3 ± 183.1 (8.3 ± 1.6 mm) eggs. Egg number in relation to CW was calculated by the formula egg number (EN) = 110.36 × CW + 90.96 (R2 = 0.948, n = 41, p < 0.0001). Regression analysis showed that fecundity was closely associated with female CW. Our results indicate that the performance of reproductive biology depends not only on continuous breeding but also on recruitment throughout the year in our study area.

scholarly journals Effectiveness of Gutting Blue Whiting (Micromesistius poutassou, Risso, 1827), in Spanish Supermarkets as an Anisakidosis Safety Measure

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 862
Author(s):  
Ana Elena Ahuir-Baraja ◽  
Lola Llobat ◽  
Maria Magdalena Garijo
Keyword(s):  
Food Safety ◽  
Direct Relationship ◽  
Infected Fish ◽  
Total Removal ◽  
Safety Measures ◽  
Blue Whiting ◽  
Total Prevalence ◽  
The World ◽  
Human Infections ◽  
Additional Safety

Anisakidosis is a parasitic zoonotic disease which can cause gastroallergic reactions in humans. In 2010, the European Food Safety Agency estimated that approximately 20,000 cases of anisakiasis had been reported across the world, with Spain having the highest number of infections in Europe. The blue whiting (Micromesistius poutassou, Risso, 1827) is one of the most widely fished species worldwide and represents around 25% of the white fish eaten in Spain. The Spanish Food Safety Authority requires obligatory evisceration of certain fish species before commercialization, but not for blue whiting. Nevertheless, some supermarkets carry this out themselves to prevent human infections and negative customer reactions deriving from the presence of ascaridoid larvae. To assess the effectiveness of eviscerations at supermarkets, a total of 320 blue whiting specimens were examined. The risk of larval migration from the visceral cavity to the musculature in gutted and ungutted fish was also assessed. Our results showed a total prevalence (25%) of ascaridoids in fish gutted at the supermarket, and a direct relationship was found between the presence of larvae in the muscle and time until evisceration. In ungutted fish, the standard length and weight were higher for infected than for non-infected fish. Also, massive infections had a higher prevalence in these larger specimens, in which the viability of larvae was also high. Larval viability was not found to be affected by a 24-h refrigeration period. Anisakis was the most prevalent genus identified in the fish examined. The results indicate that gutting at the supermarket is not an effective method for the total removal of ascaridoid larvae and that additional safety measures are advisable.

scholarly journals Genetic diversity and population structure of a mini-core subset from the world cowpea (Vigna unguiculata (L.) Walp.) germplasm collection

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Christian Fatokun ◽  
Gezahegn Girma ◽  
Michael Abberton ◽  
Melaku Gedil ◽  
Nnanna Unachukwu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Vigna Unguiculata ◽  
Germplasm Collection ◽  
Core Subset ◽  
The World

scholarly journals Reproductive Biology of Ovigerous Female Emerita emeritus (Crustacea, Decapoda) in Bengkulu Coastal Waters, Indonesia: Egg Production and Reproductive Output

2016 ◽  
Vol 74 (3) ◽  
pp. 103-109 ◽  
Author(s):  
Ouratul Edritanti ◽  
Achmad Farajallah ◽  
Yusli Wardiatno
Keyword(s):  
Embryonic Development ◽  
Surface Temperature ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Egg Production ◽  
Reproductive Output ◽  
Ovigerous Female ◽  
Abundant Species ◽  
Sea Surface ◽  
Egg Volume

Abstract Emerita emeritus is an abundant species in Bengkulu coastal waters, but the knowledge of its reproductive biology is poor. The present study was conducted to elucidate the reproductive aspects of ovigerous female E. emeritus, including fecundity, egg volume and reproductive output. This study was conducted between January 2015 and January 2016 in Bengkulu coastal waters, Indonesia. Samples were collected manually using shovels and hands. The results showed that ovigerous females occurred every month. Fecundity increased significantly in ovigerous females proportional to the size. No correlation was shown between sea surface temperature and egg production. Fecundity and reproductive output decreased throughout the embryonic development.

scholarly journals Comparative Gene Genealogies Indicate that Two Clonal Lineages of Cryptococcus gattii in British Columbia Resemble Strains from Other Geographical Areas

2005 ◽  
Vol 4 (10) ◽  
pp. 1629-1638 ◽  
Author(s):  
Sarah E. Kidd ◽  
Hong Guo ◽  
Karen H. Bartlett ◽  
Jianping Xu ◽  
James W. Kronstad
Keyword(s):  
British Columbia ◽  
Population Structure ◽  
Nucleotide Sequence ◽  
Global Scale ◽  
Cryptococcus Gattii ◽  
Temperate Climate ◽  
Molecular Type ◽  
Sequence Comparisons ◽  
The World ◽  
Clonal Population Structure

ABSTRACT Cryptococcus gattii has recently emerged as a pathogen of humans and animals in the temperate climate of Vancouver Island, British Columbia (B.C.). The majority (∼95%) of the isolates from the island belong to the VGII molecular type, and the remainder belong to the VGI molecular type. The goals of this study were to compare patterns of molecular variation among C. gattii isolates from B.C. with those from different areas of the world and to investigate the population structure using a comparative gene genealogy approach. Our results indicate that the C. gattii population in B.C. comprises at least two divergent lineages, corresponding to previously identified VGI and VGII molecular types. The genealogical analysis of strains suggested a predominantly clonal population structure among B.C. isolates, while there was evidence for sexual recombination between different molecular types on a global scale. We found no geographic pattern of strain relationships, and nucleotide sequence comparisons revealed that genotypes among isolates from B.C. were also present among isolates from other areas of the world, indicating extensive strain dispersal. The nucleotide sequence diversity among isolates from B.C. was similar to that among isolates from other areas of the world.

Evolution of a nourished sand beach under low wave energy in Thailand

Shore & Beach ◽  
2021 ◽  
pp. 36-54
Author(s):  
Jirat Laksanalamai ◽  
Nobuhisa Kobayashi
Keyword(s):  
Water Depth ◽  
Wave Energy ◽  
Surf Zone ◽  
Tidal Range ◽  
Gulf Of Thailand ◽  
Medium Sand ◽  
Sand Beach ◽  
Profile Changes ◽  
One Year ◽  
Upper Gulf Of Thailand

Sand beaches are essential for coastal tourism in Thailand, but erosion narrowed some beaches significantly over the years. Pattaya is a famous resort near Bangkok in the upper Gulf of Thailand. The Pattaya beach is microtidal with the average tidal range of 1.5 m. The average significant wave height is 0.2 m and the wave energy is low. The beach was widened by placing 130 m3/m of medium sand along the shoreline length of 2.8 km between two terminal groins constructed in 2018. The bathymetry and topography were measured in 2015, 2019, and 2020. Approximately 14% of the placed sand in the water depth less than 2 m was lost after one year, as may be expected for nourished beaches. The bathymetry change in the water depth of 2-4 m varied alongshore. The sand volume change in this offshore zone beyond the surf zone was as large as that in the landward sand placement zone. The assumption of negligible profile changes seaward of a closure depth is not applicable to this beach during 2015-2020.

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