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A new species of crown-of-thorns sea star (CoTS), Acanthaster benziei sp. nov., is described based on four specimens collected from Saudi Arabia’s Red Sea coast where it inhabits coral reefs. Species delimitation from congeners in the species complex, i.e., Acanthaster planci, Acanthaster mauritiensis and Acanthaster cf. solaris, is primarily based on distinct and diagnostic mitochondrial DNA sequence regions. Species separation of Acanthaster benziei is additionally justified due to diagnostic morphological characters: fewer arms; narrower and thinner spines; fanned spine tips in primary and latero-oral spines; a wider tip or tapering shape in circumoral spines; and rhombus-shaped oral pedicellariae.  

The microanatomy and ultrastructure of the larval excretory system of Patella vulgata L., 1758 has been examined by means of semithin and ultrathin serial sections, reconstructions, and transmission electron microscopy. The protonephridial system appears after torsion and consists of two terminal flame bulbs with narrow, ciliated ducts. Whereas the polyciliary terminal cells (cyrtocytes) are only slightly asymmetrically placed below the mantle cavity, the distal excretory ducts and their openings show remarkable asymmetry due to torsion. Further larval ultrafiltration sites with identical fine-structure (meandering slits with diaphragms covered by extracellular matrix) are present in the solitary rhogocytes (pore cells). The presence of larval protonephridia is regarded as plesiomorphic for Mollusca and the Trochozoa (Spiralia) as a whole and the specific conditions (asymmetry, simplicity) in Patella are probably plesiomorphic for the Gastropoda.

ABSTRACTThe genus Lodderena Iredale, 1924 has been classified in the Skeneidae by most recent authors. However, this family, originally characterized by their minute size, lack of nacre in the teleoconch and a rhipidoglossate radula, is currently considered to be polyphyletic assemblage, and preliminary molecular systematic data suggest exclusion of Lodderena from Skeneidae. In order to shed light on the systematic position of this genus, we provide a detailed description of the anatomy and histology of the type species, Lodderena minima (Tenison-Woods, 1878), and of L. ornata (Olsson & McGinty, 1958). The anatomical data confirm the vetigastropod-trochoid nature of Lodderena but exclude the genus from Skeneidae. Skeneidae are mainly characterized by a propodial penis, a hermaphroditic condition with separated testis and ovary, and a large receptaculum in the mantle roof. In contrast, Lodderena species lack both a copulatory organ and receptaculum, and have a true ovotestis. We also...

The microanatomy and ultrastructure of the larval excretory system of Patella vulgata L., 1758 has been examined by means of semithin and ultrathin serial sections, reconstructions, and transmission electron microscopy. The protonephridial system appears after torsion and consists of two terminal flame bulbs with narrow, ciliated ducts. Whereas the polyciliary terminal cells (cyrtocytes) are only slightly asymmetrically placed below the mantle cavity, the distal excretory ducts and their openings show remarkable asymmetry due to torsion. Further larval ultrafiltration sites with identical fine-structure (meandering slits with diaphragms covered by extracellular matrix) are present in the solitary rhogocytes (pore cells). The presence of larval protonephridia is regarded as plesiomorphic for Mollusca and the Trochozoa (Spiralia) as a whole and the specific conditions (asymmetry, simplicity) in Patella are probably plesiomorphic for the Gastropoda.