No abstract

ABSTRACT. lsogllomoll bicolor (C.B. Adams) (Bivalvia, Isognomonidae): first record to the Brazilian littoral, redescription of the species and comments on the occurrence and distribution of lsogllomoll in the Brazilian coast. The bivalve family Isognomonidae is represented in lhe Western Atlantic by lhe living genera Crena/ula Lamarck, 1804 and lsognomon Solander, 1786. I. ala/Us (Gmelin, 1791) and I. radia/us (Anlon, 1839) are lhe only Isognomonidae referred lO lhe Brazilian malacofauna. The present work refers lo lhe firsl record and geographic distribulion of l. bicolor along lhe Brazilian littoral, and presents a re-description of lhe species based on shell characlers, which include Ihose of the prodissoconch. The occurrence of l. ala/us and l. radia/us along lhe Brazilian littoral could no! be confirmed, despite the intensive search for Ihese Isognomonidae from Rio Grande do Norte Ihrough Rio Grande do Sul.

Marian, J.E.A.R. and Domaneschi, O. 2012. Unraveling the structure of squids' spermatophores: a combined approach based on Doryteuthis plei (Blainville, 1823) (Cephalopoda: Loliginidae). -Acta Zoologica (Stockholm) 93: 281-307.Male coleoid cephalopods produce elaborate spermatophores, which function autonomously outside the male body during copulation, undergoing a complicated process of evagination. In order to contribute to the understanding of this unique structure, this study investigated the morphology of the spermatophore of Doryteuthis plei applying several microscopy techniques. A hitherto unreported, much more complex structural arrangement was revealed for the loliginid spermatophore, the most striking findings being: (1) the complex, layered structure of the middle membrane, which bears an additional, chemically distinct segment surrounding part of the cement body; (2) the presence of a space between the inner tunic and middle membrane filled with a fine reticulated material; (3) the presence of stellate particles not only embedded in the spiral filament, but also closely applied to the inner membrane at the level of the cement body; (4) the presence of a pre-oral chamber in the cap region; and (5) the complex organization of the cement body, formed by two distinct layers encompassing contents of different chemical and textural properties. Careful literature reassessment suggests several of these features are common to loliginids, and to some extent to other squids. Their possible functional implications are discussed in light of our knowledge of the spermatophoric reaction mechanics.

 Abstract Sartori, A.F., Passos, F.D. and Domaneschi, O. 2006. Arenophilic mantle glands in the Laternulidae (Bivalvia: Anomalodesmata) and their evolutionary significance. -Acta Zoologica (Stockholm) 87 : 265-272The mantle margins of several anomalodesmatans bear multicellular arenophilic glands, the mucoid secretions of which attach sand grains and other foreign particles to the outer surface of the periostracum. These glands have been recorded for many of the anomalodesmatan families and are used as a key morphological character in recent attempts to unravel the evolutionary relationships within the Anomalodesmata. The glands occur in Laternula elliptica , L. truncata , L. boschasina and L. marilina , discharging from the top of muscular papillae at the distal tip of the siphons. The secretions are laid down as threads organized in longitudinal lines along the length of the periostracum that covers the siphonal walls. This is the first record of arenophilic mantle glands in members of the Laternulidae, a finding that not only broadens our current knowledge of the family's morphology, but assists in the reconstruction of anomalodesmatan evolutionary history.