منابع مشابه
Echinoderms
two fish. In the wild, kittiwakes have to learn to look for particular colours and patterns in the ocean to find the best place to fish. The researchers tried to recreate this for the captive birds by making them search for their food among a chequerboard of different coloured bowls. Chicks on the unrestricted fatty diet quickly learned which bowls contained food, but chicks on lean rations wer...
متن کاملThe evolution of neuropeptide signalling: insights from echinoderms
Neuropeptides are evolutionarily ancient mediators of neuronal signalling that regulate a wide range of physiological processes and behaviours in animals. Neuropeptide signalling has been investigated extensively in vertebrates and protostomian invertebrates, which include the ecdysozoans Drosophila melanogaster (Phylum Arthropoda) and Caenorhabditis elegans (Phylum Nematoda). However, until re...
متن کاملIntroducing some echinoderms from the Tirgan Formation, Kopeh-Dagh Basin, NE of Iran
A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and c...
متن کاملEchinoderms Have Bilateral Tendencies
Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Echinoderm larvae are bilateral during their early development. During embryonic development of starfish and sea urchins, the position and the developmental sequence ...
متن کاملAntimicrobial peptides in Echinoderms
Antimicrobial peptides (AMPs) are important immune effector molecules for invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system. Here we summarize the knowledge of such peptides in echinoderms. Strongylocins are a novel family of cysteine-rich AMPs, recently identified in the sea urchins, Strongylocentrotus droebachiensis and S. purpuratus. Although these mol...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the United States National Museum
سال: 1952
ISSN: 0096-3801
DOI: 10.5479/si.00963801.102-3302.265