Volume 25

Volume 25 Part 4

Keywords
Autofluorescence imaging; composite imaging; documentation; cephalopod paralarvae; exo-morphology;
Pages
pp. 105 -
116

In the field of zoological (and palaeontological) research, accurate documentation methods for the exo-morphology are essential. Here we propose a new method for the documentation of cephalopod paralarvae and juveniles. For documenting small-sized cephalopods autofluorescence microscopy offers numerous advantages for the presentation of outer body parts and surface structures in high resolution, partially also of internal structures such as the gladius. Structures are especially well-contrasted compared to other imaging methods, such as white-light microscopy, micro- or macrophotography. This facilitates a detailed view in high resolution at even the smallest cephalopod paralarvae. Autofluorescence imaging, combined with composite imaging, creates sharp, evenly illuminated pictures. In its higher magnification ranges it can be well compared to low-magnifying scanning electron microscopy (SEM) images, but with the advantage that the drying, mounting and preparation needed for SEM is not necessary for autofluorescence microscopy. In contrast the method enables the direct documentation of specimens inside their storage liquid. This is especially important for the investigation of rare specimens, e.g., for historical material from museum collections, or as a pre-documentation for specimens that will be processed further with an invasive method. By the use of different excitation wavelengths it is furthermore possible to either enhance surface structure details or certain inner body structures. Autofluorescence microscopy is also excellent for the imaging of certain types of small-sized fossil cephalopods, not least as the contrast against the matrix can be significantly improved. All these methods and the associated opportunities for studying cephalopod paralarvae are explored in this study.

Автофлуоресцентная микроскопия как метод документирования параларв и ювенильных особей головоногих моллюсков
Метц М.; Хауг К.; Хауг И. Т.;
Keywords
Gastropoda; prosobranchia; tetrestrial snail; Son La; endemic;
Pages
pp. 117 -
132

Son La is a province in the north-western Vietnam, the mountain chain running along the Northwest-Southeast has a phylogenetically diverse terrestrial snail fauna dominated by endemic species, which are very little known so far. This is the first checklist of the terrestrial prosobranch snails from Son La. It includes 42 species, belonging to 17 genera in five families, of which three species are endemic (Dioryx vanbuensis, Cyclophorus implicatus, and Scabrina vanbuensis). In this study two species are recorded for the first time for Vietnam (Chamalycaeus paviei, Scabrina laciniana) and 32 additional species are added to the species list of the Son La.

Чеклист и классификация наземных переднежаберных брюхоногих моллюсков из Сон Ла, северо-западный Вьетнам
До Д.С.; Нгуен Т.Х.Т.; До В.Н.;
Pages
pp. 133 -
137

In 1881 expedition of the Bremen Geographical Society collected molluscs in the north-western part of the Bering Sea off the coast of Chukotka. Unfortunately, the result of this work has not been fully appreciated by Russian malacologists since it was believed that the German expedition was working in American, not Asian waters. In this paper, On the basis of materials from the collection of the Berlin Museum of Natural History and published data it is proved, that molluscs were collected off Asian coast. Photos of the types of Gastropoda described A. Krause, are presented for the first time. "Bela" luetkeana Krause, 1885 (Mangeliidae) is attributed herein to the genus Propebela Iredale, 1918.

Виды переднежаберных брюхоногих Берингова моря, описанные А. Краузе в 1885 г.
Меркульев А.В.;
Pages
pp. 139 -
145

A new species of chiton, Leptochiton antarcticus n. sp., is described from the Southern Ocean from depths of 87-1,524 m. The new species is distinguishable from other congeneric species by the shape of head of major lateral teeth of radula, dorsal scales and anterior position of mucro.

Leptochiton antarcticus (Mollusca, Polyplacophora) – новый вид из Южного океана
Сиренко Б.И.;