RESUMO
Abstract Characteristics of the egg masses of Conus regius Gmelin, 1791 are described and figured for the first time for the coast of Brazil based on a female specimen found in the process of oviposition during the day in the state of Bahia, northeastern Brazil. Two clusters of egg masses were found in the subtidal zone of Itapuã beach attached to rocky substrate in a completely unprotected site. Oviposition likely began at least one day earlier, since the specimen had already affixed an entire egg mass and was ovipositing a second cluster at the time it was found. The egg masses were arranged in short, irregular rows of three to nine closely spaced capsules in parallel and facing the same direction. One egg mass cluster consisted of 34 capsules. Conus regius capsules are semi-transparent, vasiform in side view, higher than broad and have flattened to slightly convex sides with slight wrinkles constituted by transversal ridges. Conus regius is on the IUCN Red List of Threatened Species, but is still intensively collected in the study area and surrounding coastal environment by fishermen for the purposes of selling shells and as a food source.
Resumo Características de massas de ovos de Conus regius Gmelin, 1791 são descritas e figuradas pela primeira vez para a costa do Brasil com base em um espécime encontrado em processo de oviposição, durante o dia, no estado da Bahia, nordeste do Brasil. Dois aglomerados de massa de ovos foram achadas na zona subtidal da praia de Itapuã fixa a substrato rochoso em uma área completamente desprotegida. O processo de oviposição, provavelmente, começou um dia antes, uma vez que o espécime já tinha afixado uma massa de ovos e estava depositando um segundo aglomerado de ovos no momento em que foi encontrado. As massas de ovos apresentaram arranjos em fileiras curtas e irregulares contendo três a nove cápsulas estreitamente espaçadas, paralelas e posicionadas na mesma direção. A primeira massa de ovos observada conteve um total de 34 cápsulas. As cápsulas de Conus regius são semitransparentes, vasiformes em vista lateral (mais altas do que largas) e possuem parte lateral suavemente convexa a achatada com rugas suaves constituídas por elevações transversais. Conus regius está na Lista Vermelha de Espécies Ameaçadas da IUCN, mas ainda é intensamente coletada na área de estudo e ambientes costeiros circunvizinhos por pescadores por conta da venda das conchas e como fonte alimentar.
RESUMO
The protein-containing extracts prepared from the venom ducts of Conus austini, Conus spurius and Polystira albida caused a concentration-dependent inhibition of spontaneous contractions in guinea pig ileum. The most potent extract was obtained from P. albida venom ducts (IC50 equal 0.11 more or less 0.02 microg protein/mL). The three extracts produced a moderate inhibition of contractions elicited by acetylcholine (ACh 1 microM), suggesting the presence of anticholinergic compounds. The contractile response elicited by nicotine (10 microM) was significantly reduced by the extracts prepared from the ducts of C. austini and P. albida, which indicates that the venom produced by these species contains toxins that target neuronal nicotinic receptors. All three extracts significantly inhibited contractions evoked by histamine (0.5 miM), particularly those from C. spurius and P. albida. These findings reveal the presence of antihistaminergic compounds not previously described in any conoidean venom. Finally, we found that only the extract prepared from C. spurius ducts decreased KCl (60 mM)-induced contractions, indicating that the venom of this snail contains compounds that block voltage-dependent Ca2 more or Na more channels.
Assuntos
Animais , Feminino , Cobaias , Íleo , Venenos de MoluscosRESUMO
En la presente investigación se realizó la caracterización histológica del tubo digestivo de Polystira albida (Toxoglossa:Turridae) mediante microscopía óptica, utilizando ejemplares colectados en la Sonda de Campeche. Los resultados del análisis muestran que los labios, la boca y la probóscide presentan un epitelio cilindrico simple ciliado. La cavidad bucal tiene un epitelio cilindrico estratificado. El esófago presenta un epitelio cilindrico simple con células glandulares granulares acidófilas (naturaleza proteica), y es el sitio donde comienza la digestión. El estómago se divide en tres regiones histológicas, y tiene dos tipos de epitelio, uno cilindrico simple ciliado y otro cilindrico simple; el primero está formado por abundantes células glandulares acidófilas y basófilas (naturaleza proteica y glicoproteica', respectivamente); y el segundo contiene slo células glandulares acidófilas. La glándula digestiva está constituida por adenómeros túbulo-acinosos con células glandulares acidófilas y basófilas, en diferentes grados de secreción y los conductos presentan un epitelio cilindrico ciliado con células glandulares de ambos tipos. El intestino se divide en cinco regiones histológicas, la primera presenta un tiflosol con dos tipos de epitelio, cilindrico simple y cilindrico simple con chapa estriada; y el resto del tracto tiene un epitelio cilindrico simple ciliado con células glandulares granulares acidófilas y pliegues de diferentes tamaños que aumentan o reducen la cavidad del conducto. Se concluye que existen diferencias, principalmente en la región anterior del tubo digestivo (cavidad bucal, esófago y estómago), con respecto a las descripciones generales realizadas para la subclase Prosobranchia.
In the present investigation it was realized a histological characterization of the digestive tract of Polystira albida (Toxoglossa: Turridae), by using optic microscopy of specimens collected in Sonda de Campeche. Results of analysis show that lips, mouth and proboscis present a simple columnar epithelium with cilia. Buccal cavity has a stratified columnar epithelium. Esophagus presents a simple columnar epithelium with acidophilic granular glandular cells (proteic nature), and it is the place where digestion starts. Stomach is divided in three histological regions that have two epithelial types, simple columnar with cilia and without one; the first is formed by a lot of acidophilic and basophilic glandular cells (proteic and glycoproteic nature respectively), and the second only contains acidophilic glandular cells. Digestive gland is constituted by tubule-acinous adenomers with acidophilic and basophilic glandular cells in different grades of secretion, and ducts have simple columnar epithelium with cilia and scarcely glandular cells. Intestine is divided in five histological regions, the first presents atyphlosole with two types of epithelium, simple columnar with stratified border; the rest of the tract has simple columnar epithelium with cilia, acidophilic granular glandular cells and folds of different sizes that increase or reduce the cavity duct. Based on previous this, we conclude that in this study exist differences principally in front region of digestive tract (buccal cavity, esophagus and stomach) compared to general descriptions realized for Prosobranchia subclass.