![]() ![]() B, E, F and C, D, G are at the same scales, respectively. (H) Sketch of inner surface of a right valve. (E) Posterior view, with preserved soft parts. ![]() ![]() (C) Ventral view with valves partially opened. (A–G) From the same specimen (ZUEC BIV 8397): (A) Outer left view. elliptica is a simultaneous hermaphrodite, producing large eggs (about 200 µm in diameter), which develop as encapsulated lecithotrophic larvae ( e.g., Ansell & Harvey, 1997 Kang, Ahn & Choi, 2003). elliptica is larger and thicker-shelled ( Watson et al., 2012 Prezant, Shell & Wu, 2015) and lacks the spinules on the shell surface recorded from other species ( Checa & Harper, 2010). Compared to its lower latitude relatives of the family, L. Nicol (1966), Morton (1976), and Narchi, Domaneschi & Passos (2002) described the shell valves in detail (shown in Fig. The soft-substratum species has been collected from the intertidal to continental slope depth of about 700 m ( Waller et al., 2016), but with almost all live-collected records from depths shallower than 100 m ( Dell, 1990 Engl, 2012). The species, which is known from the region since the Pliocene ( Linse et al., 2006), is considered a sister taxon to other extant species of Laternula ( sensu lato) from Australia and the central Indo-West Pacific, with the species-level diversity of temperate and tropical members of the genus in need of investigation ( Taylor et al., 2018 MolluscaBase, 2022). King, 1832), the sole representative of the Laternulidae in Antarctic and subantarctic waters, is ubiquitous along its circumpolar distribution and is also known from the South Shetland, South Orkney, South Sandwich, South Georgia and Kerguelen Islands ( Soot-Ryen, 1951 Dell, 1990). This study reevaluates the available anatomical data in the literature, both supplementing and correcting previously published accounts. Among the noteworthy findings are the presence of well-developed siphons furnished with sensory tentacles at its tips, some of which bearing eyes large, folded gills and labial palps capable of sorting the material entering the mantle cavity an inter-chamber communication in the posterior region of the mantle cavity an ample ventral mantle fusion with an anterior pedal gape the absence of a 4 th pallial opening and the absence of a ligamental lithodesma in adult specimens. Special focus is placed on the pallial organs (including elucidation of cleansing and feeding sorting mechanisms in the mantle cavity) and the musculature. Based on observations of aquarium-maintained living animals at the Brazilian Comandante Ferraz Antarctic Station, gross-morphological dissections, and histological sectioning, the comparative anatomy, functional morphology, and aspects of behavior of L. In contrast, its anatomy has remained poorly known, with prior published data limited to partial descriptions based on chemically preserved specimens. A keystone species of the regional benthic communities, it has reached model status, having been studied in hundreds of scientific works across many biological disciplines. King, 1832) is the sole representative of the anomalodesmatan family Laternulidae and the largest bivalve in the Antarctic and Subantarctic. ![]()
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