1,721,012 research outputs found
A new species of Gregorioiscala (Gastropoda: Epitoniidae) from the Red Sea
No full textA new species of Gregorioiscala Cossman, 1912 (Gastropoda: Epitoniidae) is described based on shells collected in the bathyal zone of the central Red Sea, off Sudan. Gregorioiscala federicoi n. sp. is the first representative of this bathyal genus in the Red Sea. Type specimens of Scala sumatrensis Thiele, 1925, Scala punctata Thiele, 1925, and Scala costigera Thiele, 1925 are illustrated
Morphology of setae in regenerating caudal adhesive pads of the gecko Lygodactylus capensis (Smith, 1849)
Full text linkAfter tail loss in the African gecko Lygodactylus capensis (Smith, 1949) a new tail is regenerated, including caudal adhesive pads. The axial skeleton of the regenerating tail consists in an elastic cartilaginous tube replacing the original vertebrae that allows interacting with the substrate like in the original tail. The formation of adhesive setae has been analyzed using transmission and scanning electron microscopy coupled to immunolabeling for Corneous Beta Proteins. During progressive stages of epidermal differentiation new setae are developed at stage 4 of the shedding cycle and contain Corneous Beta Proteins. These structural proteins are faintly localized in the Oberhautchen but are abundant in the beta-layer, indicating that the two epidermal layers have a different protein composition. The setae originate from the growth of Oberhautchen spinulae into the cytoplasm of clear cells and the latter produce a thick fibrous meshwork of keratin and other unknown proteins localized around the growing setae. This cytoskeleton likely allows molding tail setae like for digital setae. A graded development of setae is observed from the base to the tip of regenerated pads and from the periphery to more central areas. The terminal end of the setae is subdivided into numerous filamentous spatulae that increase the adhesion contact. Sensory boutons are frequently detected at the margin of tail scales and adhesive pads, likely improving compliance with the substrate. The present study indicates that tail regeneration is a convenient experimental model to analyze adhesive setae formation, microstructures that allow to these lizards climbing vertical and arboreal substrates
Taranidaphne dufresnei (Mollusca: Gastropoda: Turridae), new genus and species from Yemen, Red Sea
No full textBased on specimens from the Museo di Zoologia dell' Universitè di Bologna, Taranidaphne dufresnei gen. & sp. nov. is here described from Yemen, Red Sea and Gulf of Aden. The new genus is compared to Taranis Jeffreys, 1870, which it resembles mainly in apertural features. A total of four recent species are at present included in the genus. A redescription of Daphnella (Pleurotomella) amphitrites Melvill & Standen, 1903, and notes on Daphnella (Pleurotomella) nereïdum Melvill & Standen, 1903, species assigned to the new genus and originally described from the Gulf of Oman, are included. Bela erythraea Jousseaume, 1895, from Atacka, Suez, Red Sea, is here regarded as a synonym of Pleurotoma (Bela) hongkongensis Sowerby, 1888, from Hong Kong, a species also referred to Taranidaphne. The lectotype and a paralectotype of Bela erythraea are figured. A lectotype for Daphnella (Pleurotomella) amphitrites is designated and figured; syntypes of Pleurotoma (Bela) hongkongensis and Daphnella (Pleurotomella) nereïdum are figured for the first time
Yoldiella seguenzae, a new species of nuculanidae (bivalvia; nuculoida) from the Mediterranean Sea
No full textA new species, Yoldiella seguenzae (Bivalvia, Nuculoida), from a deep sea community off the north east coast of Sardinia (Mediterranean Sea), is described. Morphometrical and statistical comparison with the very similar Yoldiella philippiana (Nyst, 1845), and general morphological comparison with other Mediterranean and Atlantic species support the distinctivness of Y. seguenzae which is distributed in deep waters of the Central Mediterranean Sea, Alboran Sea and the Atlantic Ocean
Epitonium (Asperiscala?) oliverioi, a new species of Epitoniidae (Gastropoda) from Madagascar
No full textEpitonium (Asperiscala?) oliverioi new species (Gastropoda, Ptenoglossa, Epitoniidae) characterized by two different teleoconch microsculptures is described from the Tuléar region (SW Madagascar). A brief comparison of its spawn and radular morphology with those known of other epitoniids is also given in order to provide further characters for specific and supraspecific classification
First record of Munidopsis acutispina Benedict, 1902 (Decapoda, Anomura, Galatheidae) in the Mediterranean Sea
No full textThe Polyplacophora of Easter Island
No full textThree species of Polyplacophora are found on Easter Island: Plaxiphora inercatoris Leloup, 1936, which was the only known species for 50 years, Rapanuia disalvoi gen. & sp. nov., and Weedingia cf. mooreana Kaas, 1988. The living specimens of Rapanuia disalvoi were collected in 1984-1985, and several hundred valves in more recent years, but no additional live specimens have been found. This species, at first, appears very similar to Tonicia, but the absence of pectination on the teeth of the insertion lamina leads us to define the new genus Rapanuia and consequently the new subfamily Rapanuiinae. Three valves of a third chiton species, similar to Weedingia mooreana, were also discovered. The differences with W. mooreana are discussed
Electron microscopic analysis in the gecko Lygodactylus reveals variations in micro-ornamentation and sensory organs distribution in the epidermis that indicate regional functions
Full text linkPossible pattern variations of micro-ornamentation in different areas of the skin in the gecko Lygodactylus have been analyzed by scanning and transmission electron microscopy. A map of micro-ornamentation present in various areas of the skin has been obtained. Differences in micro-ornamentation pattern and sensory organ distribution were detected. The “spinulated pattern” consists of shorter spinulae in dorsal versus ventral scales, and spinules are shorter in inner scale surface and hinge regions with respect to the outer scale surface. The spines derive from the accumulation of struts of corneous material mainly composed of corneous beta proteins (CBPs, formerly indicated as beta-keratins) that merge into pointed micro-ornamentation. The 3D-accumulation of CBPs within Oberhautchen cells can vary in some regions of different scales during Oberhautchen-beta cell differentiation, perhaps also under physical tensile forces derived from continuous scale growth. Three other main patterns of micro-ornamentation were detected and indicated as “corneous belts,” “corneous dendritic ramification,” and “serpentine-pit and groove.” These variations from the typical spinulated pattern present in gecko epidermis are interpreted as transitional regions where the accumulation of corneous material in Oberhautchen cells that merges with underlying beta-cells gives rise to nonspinulated surfaces. Spinulated sensory organs with bristles and lenticular-shaped or knob-like tactile corpuscles are more numerous in ventral scales of the tail tip close to adhesive pads and near the digital pads. These regions are likely those most involved in the fine control of movements and response to vibrational stimuli derived from air and objects movements, including potential preys or predators
A new species of Ischnochiton (Mollusca: Polyplacophora) from the Pleistocene of S. Italy
No full textA new species of Ischnochiton from the late Pleistocene of Archi S. Francesco (Reggio Calabria) is described in this paper. Valves of Ischnochiton crovatoi sp. nov. were found in the sandy-pebbly marine sediments of Archi S. Francesco (located on the left side of the Valley of the river Torbido), very rich in mollusks of infralittoral to circalittoral facies. The new species is characterized by the tegmental sculpture of head valve, lateral areas of intermediate valves and postmucronal area of tail valve consisting of nodulose radial riblets. The differences between the new specie and I. rissoi (Payraudeau, 1826) and I. zbyi Dell’Angelo & Silva, 2003 are discussed
First record of Munidopsis acutispina Benedict, 1902 (Decapoda, Anomura, Galatheidae) in the Mediterranean Sea
No full textThe minute squat lobster Munidopsis acutispina Benedict, 1902 is recorded for the first time from bathyal grounds in the Mediterranean Sea. It can easily be distinguished from the two species of Munidopsis previously known from the Mediterranean, for the surface of the carapace covered with squamous spiniform tubercles. As the available illustrations of M. acutispina are somehow inadequate, the species is briefly redescribed and illustrated based on the new material and compared with its closest relatives, that are found in the western Atlantic and eastern Pacific Oceans
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