نتایج جستجو برای: diadema setosum

تعداد نتایج: 386  

Journal: :The Journal of experimental biology 2010
D Schleicherova M C Lorenzi G Sella N K Michiels

Hermaphroditism and gonochorism are two contrasting forms of sexuality. Hermaphroditic species are generally seen as species adapted to conditions of low density, stabilized by poor mate search efficiency and high costs of searching. They can adjust allocation of reproductive resources to each sex function in response to current social conditions, making reproduction more efficient, at least in...

ژورنال: پژوهش های جانوری 2019

به منظور بررسی تنوع مارهای منطقه‌ی سیستان، 45 حلقه مار از شهرستان‌های زابل، زهک، هیرمند، نیمروز و هامون مورد بررسی ریخت‌شناسی قرار گرفتند. بر اساس نتایج این مطالعه، هفت گونه متعلق به شش جنس از دو خانواده در منطقه‌ی سیستان مورد شناسایی قرار گرفتند که عبارتند از: Boiga trigonatum، Lytorhynchus maynardi،Platyceps karelini ، Platyceps rhodorachis، Psammophis schokari وSpalerosophis diadema از خانوا...

2015
Elizabeth Sherman Alex Ford

The massive die-off of the long-spined sea urchin, Diadema antillarum, a significant reef grazer, in the mid 1980s was followed by phase shifts from coral dominated to macroalgae dominated reefs in the Caribbean. While Diadema populations have recovered in some reefs with concomitant increases in coral cover, the additional threat of increasing temperatures due to global climate change has not ...

Journal: :Proceedings. Biological sciences 2001
H A Lessios M J Garrido B D Kessing

The sea urchin Diadema antillarum was the most important herbivore on Caribbean reefs until 1983, when mass mortality reduced its populations by more than 97%. Knowledge of its past demography is essential to reconstruct reef ecology as it was before human impact, which has been implicated as having caused high pre-mortality Diadema abundance. To determine the history of its population size, we...

Journal: :Revista de saude publica 2007
Marcos Romano Sérgio Duailibi Ilana Pinsky Ronaldo Laranjeira

OBJECTIVE Alcohol use is a public health problem. Commercial availability is an important factor that encourages the use of alcohol by young people. The aim of the study was to assess how often young people under 18 could buy alcohol in shops METHODS Adolescents from 13 to 17 attempted to purchase alcoholic beverages at a random sample of shops in the cities of Paulinia (n=108) and Diadema (n...

Journal: :Evolution & development 2015
Santosh Jagadeeshan Simon E Coppard Harilaos A Lessios

Many free-spawning marine invertebrates, such as sea urchins, lack any courtship or assortative mating behavior. Mate recognition in such cases occur at the gametic level, and molecules present on the sperm and egg are major determinants of species-specific fertilization. These molecules must also coevolve in relation to each other in order to preserve functional integrity. When sea urchins rel...

Journal: :Revista de biologia tropical 2010
F Martín Blanco G González Sansón F Pina Amargós L Clero Alonso

The 1983-1984 mass mortality event of Diadema antillarum affected more than 93% of the total Caribbean population. Although there are no records about the status of Diadema populations before and after die-off on Cuban reefs, anecdotal information suggests that populations were struck. We analyzed spatial variation in the abundance and size structure of D. antillarum in 22 reefs sites in Jardin...

Journal: :Cercetări Arheologice 1992

2014
Hiran A Ariyawansa Rungtiwa Phookamsak Saowaluck Tibpromma Ji-Chuan Kang Kevin D Hyde

We revisit the family Diademaceae based on available sequence data and morphology. Diademaceae is characterized by ascomata opening with a flat circular lid and fissitunicate, short orbicular frequently cylindrical, pedicellate asci. Ascospores are frequently circular in section but narrowing to one end with three or more transverse septa, without longitudinal septa, and mostly with a thick she...

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