Distribution, Population Structure, -Population Biomass and Morphological Characteristics of the Tunicate Pyura stolonifera in the Bay of Antofagasta, Chile

2000 ◽  
Vol 21 (2) ◽  
pp. 161-174 ◽  
Author(s):  
Juan C. Castilla ◽  
Ricardo Guinez ◽  
Jorge L. Alvarado ◽  
Cristian Pacheco ◽  
Manuel Varas
2019 ◽  
Vol 76 ◽  
pp. 388-402 ◽  
Author(s):  
Geumhee Yun ◽  
Hansaem Lee ◽  
Yongsuk Hong ◽  
Sungpyo Kim ◽  
Glen T. Daigger ◽  
...  

1978 ◽  
Vol 10 (4) ◽  
pp. 599
Author(s):  
Maraia Aspers ◽  
Susanne Sylven ◽  
JA Eriksson ◽  
M Wilhelmson

2019 ◽  
Vol 01 (01) ◽  
pp. 01
Author(s):  
Eniade Abiodun Adeyemi ◽  
Odedeyi Dominic Olabode ◽  
Bello-Olusoji A Oluayo ◽  
Adebayo Olabode Thomas ◽  
Agyakwah Seth Koranteng

Botanica ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 111-120
Author(s):  
Birutė Karpavičienė ◽  
Giedrė Elzbieta Mlečkaitė

AbstractThe morphological variation and population structure were studied in seven populations of Polygonatum multiflorum and 19 populations of P. odoratum. The mean number of flowers per shoot and per inflorescence as well as inflorescence number per shoot in both species correlated negatively with total tree and shrub canopy cover, while the mean number of flowers per inflorescence in P. odoratum correlated positively with the soil pH. The shoot density and life stage composition in P. odoratum populations depended on total tree and shrub canopy cover, which negatively correlated with the density of generative shoots in populations of both species. The results of this study revealed the crucial effect of light availability expressed via total tree and shrub canopy cover in the habitats of Polygonatum species to their flowering intensity and population structure.


2018 ◽  
Vol 15 (2) ◽  
Author(s):  
Bahtiar, Hamzah, M Dan Hari, H

ABSTRAKPokea merupakan bivalvia air tawar yang hidup di segmen muara. Bivalvia ini terusmengalami tekanan sejalan dengan peningkatan aktivitas kegiatan penangkapan danmenurunnya kualitas perairan. Penelitian ini bertujuan untuk mengetahui struktur danpertumbuhan populasi kerang pokea di Sungai Pohara Sulawesi Tenggara. Penelitian inidilaksanakan di segmen muara Sungai Pohara selama setahun dari bulan Maret 2007-Februari2008. Parameter populasi (L∞ dan K) dan to masing-masing dianalisis dengan menggunakanpergerakan modus frekuensi panjang dan nilai L0=0.025. Pola pertumbuhan dianalisismenggunakan inverse von Bertalanffy sedangkan struktur populasi dianalisis menggunakandistribusi normal dari plot Bhattacharya yang secara keseluruhan terakomodasi pada programFiSAT II versi 3.0. Hasil penelitian menunjukkan bahwa lebar asimtotik dan koefisienpertumbuhan jantan dan betina masing-masing yaitu 7.16 cm, 0.59 dan 6.92 cm, 0.96. Olehkarenai tu, pertumbuhan pokea betina lebih cepat dibandingkan pokea jantan. Populasikerang pokea tersebar pada berbagai kelompok ukuran yang mewakili ukuran muda, dewasadan tua dengan nilai tengah berada pada 1.49 dan 6.01 yang menyebar pada tiga kelompokukuran. Kelompok ukuran dominan pada jantan betina relatif berbeda yang tersebar padanilai tengah masing-masing 1cm dan 2cm. Secara umum, struktur populasi pokea di SungaiPohara relatif stabil.Kata kunci : pokea, pertumbuhan, struktur, populasi, sungai, PoharaABSTRACTPokea clam was fresh water bivalve that lived on well into estuary segments. Thisbivalve have experienced in under pressure as activity increase in fishing events and decreasein water quality. This research aimed to understand the structure and growth population ofpokea clam in Pohara river on Southeast Sulawesi. This research was conducted in estuarysegment of Pohara river from March 2007 to February 2008. Parameters of population (L∞dan K) and to were analyzed by using movements in modus of length frequency andLo=0.025. Growth pattern was analyzed by using von Bertalanffy inverse, and populationstructure was analyzed by using normal distribution from Bhattacharya plot with fullaccommodation on FiSAT II version 3.0. The results of this research indicated thatasymptotic width and growth coefficient for male and female were 7.16 cm, 0.59 cm, and0.96 cm. Therefore, the growth of female pokea was faster than male. Pokea clam populationspread to several size groups that represented as young, adult, and old with median 1.49 and6.01. The dominant length measurement on male and female was relatively different whichpropagated in median 1 cm and 2 cm. Generally, population structure of pokea clam inPohara river was relatively stable.Keyword: pokea, growth, structure, population, river, Pohara


2008 ◽  
Vol 55 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Joost A.M. Raeymaekers ◽  
Tine Huyse ◽  
Hannelore Maelfait ◽  
Bart Hellemans ◽  
Filip A.M. Volckaert

2022 ◽  
Vol 50 (1) ◽  
pp. 54-60
Author(s):  
Kieu Thi Huyen ◽  
Tran Nguyen Ngoc ◽  
Ha Thi Hue ◽  
Vo Van Quy ◽  
Nguyen Quang Linh

2021 ◽  
Author(s):  
V. Als ◽  
A. Narendra ◽  
W. Arthofer ◽  
P. Krapf ◽  
F. M. Steiner ◽  
...  

AbstractForaging ants face many dangers in search of food and often need to defend their prey to ensure the colony’s survival, although ants may also follow a peaceful foraging strategy. A non-aggressive approach is seen in the Australian bull ant Myrmecia nigriceps, in that workers of neighboring nests sometimes share foraging trees. In this study, we observed 31 nests at Mount Majura Nature Reserve in Canberra (Australia), 12 of which shared a foraging tree with at least one other nest in at least one of three nights. We genotyped 360 individuals at five published microsatellite loci and further established a set of nine polymorphic loci for M. nigriceps. Our results revealed a significant correlation between tree sharing and geographical distance between nests. We found no correlation between internest relatedness and tree sharing, geographical distance between nests and internest relatedness, and intranest relatedness and tree sharing. We further investigated the colony structure of M. nigriceps. All colonies were monodomous; the number of queens per colony ranged from one to two, and the number of fathers from one to three. No instances of worker drifting were found in this study.


Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 154-161 ◽  
Author(s):  
Valérie Dumas ◽  
Stéphane Herder ◽  
Aïcha Bebba ◽  
Cécile Cadoux-Barnabé ◽  
Christian Bellec ◽  
...  

In West Africa, Onchocerca volvulus, the cause of human onchocerciasis, is transmitted by sibling species of the Simulium damnosum complex. Little is known about blackfly intraspecific variability and its consequences on vectorial capacity. This study reports the use of microsatellite markers for differentiating populations of S. damnosum s.l. Five microsatellite loci were characterized and used to analyze individuals from two savannah populations in Mali, 120 km apart. Four loci were highly polymorphic, having 8-12 alleles per locus and gene diversities ranging from 77.9 to 88.2%. A significant heterozygote deficiency was observed in the two populations. This may arise from inbreeding, population structure (the Walhund effect), or the presence of null alleles. To test this last hypothesis, new primers were designed for two loci and used to analyze homozygous individuals. After correcting for null alleles, heterozygote deficit persisted. Population subdivision in the two foci remains the most likely explanation. Our results indicate that microsatellite markers could differentiate fly populations, making them valuable tools for the study of population genetic structure.Key words: Simulium damnosum s.l., microsatellites, polymorphism, population structure, population genetics, null alleles.


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