Abstract In Odonates, female colour polymorphism is common and implies the presence of two or more types with different colours behaviours. To explain this phenomenon, several hypotheses have been proposed that consider morph frequency, population density, parasites, mating behaviour. We studied blue-tailed damselfly Ischnura elegans , a species blue androchrome gynochrome morphs (the green inf...

Since the early observations of tidal rhythms in Convoluta (Gamble & Keeble, 1903, 1904) and in Actinia (Bohn, 1906) much experimental work on rhythms of behaviour in intertidal animals has been concerned with such phenomena as oxygen uptake and colour changes. Gompel (1937) demonstrated tidal rhythms of oxygen consumption in Patella, MytUus and Hatiotis and similar rhythms have been shown more...

In embryos of the gastropod Ilyanassa obsoleta, the first-quartet micromeres of the A, B and C lineages (1a, 1b, and 1c) are each competent to form an eye in response to signaling from the 3D cell. The first-quartet micromere of the dorsal D lineage (1d) is smaller than the others, divides at a slower rate, and lacks the ability to form an eye. These properties of 1d all depend on inheritance o...

Understanding the individual and interactive roles of consumer species is more than academic when the host plant is a subject of intense conservation interest. In a mesocosm experiment, we compared effects of common invertebrate grazers in San Francisco Bay seagrass (Zostera marina, eelgrass) beds, finding that some species (a native opisthobranch, Phyllaplysia taylori; a native isopod, Idotea ...

:  Life history stages of Pleurogonius malaclemys were investigated in wild populations of the eastern mudsnail ( Ilyanassa obsoleta ) and diamondback terrapin ( Malaclemys terrapin ) in New Jersey, New York, and Rhode Island between 2011 and 2015, and laboratory experiments investigating the settling preference of metacercarial cysts of P. malaclemys were conducted. Cysts of P. malaclemys were...

Although mercury (Hg) is a well-studied contaminant, knowledge about Hg accumulation in snakes is limited. The authors evaluated Hg bioaccumulation within and among four snake species (northern watersnakes, Nerodia sipedon; queen snakes, Regina septemvittata; common garter snakes, Thamnophis sirtalis; and rat snakes, Elaphe obsoleta [Pantherophis alleghaniensis]) from a contaminated site on the...

Scarab beetles (Coleoptera: Scarabaeidae) are one of the most limiting pests avocado in Antioquia Department, Colombia. The establishment management strategies to control these has been difficult because species causing damage fruit and young leaves have not identified. Selected commercial fields were surveyed at different times d for scarab beetle adults affecting small leaves, as well other p...

In the embryos of the gastropod Ilyanassa obsoleta, the development of several ectodermal structures requires an inductive interaction between the micromeres and the D macromere. The first quartet micromeres (1a, 1b, 1c and 1d) contribute to the head of the larva and descendants of 1a and 1c normally develop the eyes. The eyes do not develop if 1a and 1c are removed at the eight-cell stage. How...

Especialmente desde una perspectiva jurídica, el estudio analiza las medidas en ámbito educativo adoptadas a nivel mundial y España razón del coronavirus: la “suspensión sin suspensión” de educación especialmente través enseñanza digital. Sin embargo, digital se ha considerado “inferior”, “excepcional” sólo “complementaria” presencial fuente graves barreras peligros para educación. Así sido int...