Oscar Roberto Chaparro

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Evolutionary transitions between different modes of development in marine invertebrates are thought to be biased toward the loss of feeding larvae. Because the morphology of feeding larvae is complex and nonfeeding larvae or encapsulated embryos with benthic development often have simplified morphologies, it is presumed to be easier to lose a larval stage(More)
Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to(More)
Brooding in invertebrates serves to protect embryos from stressful external conditions by retaining progeny inside the female body, effectively reducing the risk of pelagic stages being exposed to predation or other environmental stressors, but with accompanying changes in pallial fluid characteristics, including reduced oxygen availability. Brooded embryos(More)
The gene encoding rat cystatin S (Cys S), a salivary gland-specific secretory protein, has CAAT and TATA boxes upstream of the inititation codon (Cox and Shaw, 1992), and contains regions that resemble those of other hormonally responsive eukaryotic genes. The 5'-flanking sequence of the rat Cys S gene has a potential CREB/AP-1 binding site (Rupp et al.,(More)
Gaimardia bahamondei is a small gonochoric bivalve which lives attached to subtidal algae. Females brood their embryos in the suprabranchial region of the pallial cavity, in close proximity to the gill filaments. We found no significant difference in clearance rate between males (non-brooders) and females (brooders), regardless of the numbers of embryos in(More)
Organisms that encounter stressful situations in nature often cope using behavioral (e.g., avoidance) or physiological tactics. In sessile mollusks, the only available behavioral option in dealing with salinity stress is to “clam up”, isolating their tissues from the environment. Though effective in the short term, prolonged isolation can have detrimental(More)
Shallow-water coastal areas suffer frequent reductions in salinity due to heavy rains, potentially stressing the organisms found there, particularly the early stages of development (including pelagic larvae). Individual adults and newly hatched larvae of the gastropod Crepipatella peruviana were exposed to different levels of salinity stress (32(control),(More)
This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the(More)
Parasympathetic innervation of rat submandibular and parotid glands regulates saliva volume, its rate of secretion and its composition. It also has a regulatory role in hypertrophy and hyperplasia of salivary glands, and in the expression of specific sets of genes. Rat cystatin S is a member of family 2 of the cysteine proteinase inhibitor superfamily.(More)
The rat submandibular gland is innervated by both sympathetic and parasympathetic branches of the autonomic nervous system which, in turn, regulate the secretory function of the gland. Parasympathetic innervation of rat submandibular glands is present at birth; in contrast, sympathetic innervation reaches the glands by postnatal day 5. Isoproterenol (IPR),(More)
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