Mixed effects of elevated pCO2 on fertilisation, larval and juvenile development and adult responses in the mobile subtidal scallop Mimachlamys asperrima (Lamarck, 1819)

Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world's oceans at predicted future pCO2 levels.

Monography of the family Unionidae, or Naiades of Lamarck (fresh water bivalve shells,) of North America, : illustrated by figures drawn on stone from nature. / by T.A. Conrad ...

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Escala y talla de primera madurez gonadal en “NAVAJA” Tagelus dombeii (Lamarck, 1818), entre las zonas Parachique - Las Delicias, 2009

Para el estudio de la gametogénesis, escala de madurez y estimación de la talla de primera madurez gonadal de “navaja” Tagelus dombeii, las muestras procedieron de las zonas Caleta de Parachique y Las Delicias, y fueron colectadas a bordo de embarcaciones marisqueras por buzos artesanales, durante Enero – Diciembre del año 2009. La zona para tomar las muestras comprendieron desde los grados 05º 40' 33.3'' (LS) hasta 05º 49' 21.8'' (LS). En el estudio de la gametogénesis, se observó que los ovarios presentaron tres tipos de ovocitos: ovocito inmaduro (OI), ovocito en maduración (OEM) y ovocito maduro (OM), además del ovocito atrésico (OA) para las hembras, mientras que para los machos las células sexuales encontradas fueron: espermatogonio = SG, espermatocito = SC y espermatozoide = SP. La escala microscópica de madurez gonadal para “navaja” T. dombeii fue establecida con seis estadios, siendo estos: Virginal = 0, Reposo = I, En Maduración = II, Maduro =III, Desovante/Expulsante = IV y Recuperación = V. Así mismo, se estableció, que la talla de primera madurez gonadal es de 61 mm de longitud total (LT) para las hembras y 58 mm para machos, obteniendo un promedio de 58 mm LT. Mientras que la talla de primer desove/expulsión fue de: 67 mm (LT) para hembras y 66 mm LT para machos siendo promedio para ambos sexos de 66 mm LT. Además, se reporta la capacidad de T. dombeii de cambiar el sexo de hembra a macho (hermafroditismo protógino).

The conchologist's text-book : embracing the arrangements of Lamarck and Linnaeus, with a glossary of technical terms /

Mode of access: Internet.

The history of creation, or, The development of the earth and its inhabitants by the action of natural causes : a popular exposition of the doctrine of evolution in general, and of that of Darwin, Goethe and Lamarck in particular /

Photocopy. Chicago, Ill. : University of Chicago Library, Dept. of Photoduplication, 1988.

Arboretum forestier; essai d'une classification des arbres, arbrisseaux et arbustes qui composent les forêts de la France, etc., disposés d'après la méthode analytique de M. Lamarck, avec indication des familles naturelles auxquelles ils appartiennent, suivi du tableau (latin et français) de l'École de botanique forestière.

Mode of access: Internet.

Sur le bulla aperta Lin., Bullaea de Lamarck.

Mode of access: Internet.

Disposition méthodique des espèces récentes et fossiles des genres pourpre, ricinule, licorne et concholépas de m. de Lamarck, et description des espèces nouvelles ou peu connues, faisant partie de la collection du Muséum d'histoire naturelle de Paris.

"Lue à l'Académie des sciences de l'Institut, le 26 mars 1832."

The conchologist's text-book, Embracing the arrangements of Lamarck and Linnaeus, with a glossary of technical terms.

Mode of access: Internet.

A manual of conchology, according to the system laid down by Lamarck, with the late improvements by De Blainville exemplified and arranged for the use of students.

Mode of access: Internet.

Natürliche Schöpfungsgeschichte. Gemeinverständliche wissenschaftliche Vorträge über die Entwickelungslehre im Allgemeinen und diejenige von Darwin, Goethe und Lamarck im Besonderen.

"Verzeichniss der im Texte mit Ziffern angeführten Schriften, deren Studium dem Leser zu empfehlen ist": p. 796-801.

Lamarck als begründer der descendenz lehre

Mode of access: Internet.

Sub lethal mercuric chloride toxicity induced stress related alterations in the epithelial lining of foot of the freshwater mussel Lamellidens marginalis (Lamarck)

Sub lethal (0.2 ppm) mercuric chloride induced stress related histopathological alterations in the epithelial linings of foot (podium) of the edible freshwater mussel Lamellidens marginalis (Lamarck) were studied using histochemical techniques up to 60 days of exposure. The histomorphological changes were manifested only slowly and its intensity was somewhat proportional to the duration of exposure. The immediate response of the exposed mussels was the altered mucous secretion. There was a progressive incorporation of sulphated glycoproteins into the secretory contents of the mucous cells especially in the first half of the experiment. Marked histopathological changes including necrosis, appearance of pyknotic nuclei, sloughing of epithelial cells and appearance of non-tissue spaces, etc., started appearing during the later half of the experiment. The fag end of the experiment, which witnessed prominent histomorphological changes, was accompanied by highly decreased mucous secretion. KEYWORDS: heavy metal toxicity, mercuric chloride, Lamellidens marginalis, freshwater mussel, histopathology.

A mesocosm analytical study on the impact of freshwater mussel (Lamellidens marginalis Lamarck) mediated bioturbation and biodeposition on some ecological factors of a freshwater lake

The biotic potential of the benthic filter feeding freshwater bivalve mollusc Lamellidens marginalis (Lamarck) influencing the nutrient dynamics of the bottom sediments of the lake by means of biodeposition and bioturbation activities were analysed using a lake mesocosm experiment. Five control as well as experimental mesocosms was maintained up to 60 days (d). The factors studied included the percentage of water content of the sediment, percentage of total nitrogen, percentage of organic matter along with the total phosphorus and humic acid content. While total phosphorus and humic acid content of the experimental mesocosoms showed gradual and significant increases from 30d of the experiment to reach the maximum levels after 60d, the percentage of organic matter registered significant increases right from 15d onwards and reached the maximum values after 60d. On the other hand, while the percentage of water content of the sediments of the experimental mesocosoms increased only up to 30d experiment, percentage of nitrogen was increased during the first half and at the fag end of the experiment. All the investigated ecological factors were found to be significantly influenced by the presence of L. marginalis in the experimental mesocosms. The study indicated that the mussel influence the nutrient dynamics of the inhabitant ecosystem through the processes of excretion, biodeposition of pseudofaeces and faeces, along with the bioturbation of the sediments brought about by their ploughing movements. KEYWORDS: freshwater mussel, Lamellidens marginalis, bioturbation, biodeposition, mesocosms.