Increase of macromolecule synthesis after hatching of Concholepas concholepas veliger larvae: Effect of sulfate in the synthesis of proteoglycans

1990 ◽  
Vol 96 (3) ◽  
pp. 613-619 ◽  
Author(s):  
Enrique Brandan ◽  
Mauricio González ◽  
Roberto González-Plaza ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Concholepas Concholepas ◽  
Veliger Larvae

A scanning electron microscopic study of the veliger larvae of the scallop argopecten purpuratus

1988 ◽  
Vol 46 ◽  
pp. 284-285
Author(s):  
G.C. Bellolio ◽  
K.S. Lohrmann ◽  
E.M. Dupré
Keyword(s):  
Morphological Description ◽  
Electron Microscopic ◽  
Larval Stages ◽  
Scanning Electron Microscopic Study ◽  
The Pacific ◽  
Argopecten Purpuratus ◽  
Veliger Larvae ◽  
20 Nm ◽  
Ethanol Series ◽  
Scanning Electron

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.

Effects of ocean acidification on larval development and early post-hatching traits in Concholepas concholepas (loco)

2014 ◽  
Vol 514 ◽  
pp. 87-103 ◽  
Author(s):  
PH Manríquez ◽  
ME Jara ◽  
ML Mardones ◽  
R Torres ◽  
NA Lagos ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Larval Development ◽  
Concholepas Concholepas

Planktivory by alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) on microcrustacean zooplankton and dreissenid (Bivalvia: Dreissenidae) veligers in southern Lake Ontario

1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman
Keyword(s):  
Laboratory Experiments ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Field Observations ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Consumption Rates ◽  
South Shore ◽  
Young Of The Year ◽  
Veliger Larvae

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.

scholarly journals Mexican dancer in Ecuador: molecular confirmation, embryology and planktotrophy in the sea slug Elysia diomedea

2020 ◽  
Vol 52 ◽  
Author(s):  
Lola Moreano-Arrobo ◽  
Oscar D. Pérez ◽  
Federico D. Brown ◽  
Fernanda X. Oyarzún ◽  
Cristian B. Canales-Aguirre
Keyword(s):  
Genetic Information ◽  
Ex Situ ◽  
Adult Size ◽  
Mtdna Sequences ◽  
Cell Stage ◽  
Egg Capsules ◽  
Northeast Pacific ◽  
Morphological Differences ◽  
General Aspects ◽  
Veliger Larvae

Elysia diomedea varies in adult size and color across its geographical distribution in Ecuador. Because of morphological variation and the absence of genetic information for this species in Ecuador, we analyzed mtDNA sequences in three populations (Ballenita, La Cabuya, and Mompiche) and confirmed that (1) individuals from the three locations belonged to E. diomedea and (2) that there was no population structure that could explain their morphological differences. Next, we analyzed general aspects about the reproductive biology and embryology of this species. Live slugs from the Ballenita population were maintained and reproduced ex situ. Egg ribbons and embryos were fixed and observed by brightfield and confocal microscopy. We observed a single embryo per capsule, 98 embryos per mm2 of egg ribbon, and compared the cleavage pattern of this species to other heterobranchs and spiralians. E. diomedea early development was characterized by a slight unequal first cleavage, occurrence of a 3-cell stage in the second cleavage, and the formation of an enlarged second quartet of micromeres. We observed clear yolk bodies in the egg capsules of some eggs ribbons at early stages of development. Both reproductive and embryological characteristics, such as presence of stomodeum in the larva, and ingestion of particles after hatching confirmed the planktotrophic veliger larvae of this species, consistent with the majority of sacoglossans from the Eastern and Northeast Pacific Oceans.

Effect of the earthquake-tsunami (Chile, 2010) on toxic metal content in the Chilean abalone mollusc Concholepas concholepas

2019 ◽  
Vol 169 ◽  
pp. 418-424 ◽  
Author(s):  
J. Tapia ◽  
F. Villagra ◽  
C. Bertrán ◽  
J. Espinoza ◽  
S. Focardi ◽  
...  
Keyword(s):  
Metal Content ◽  
Toxic Metal ◽  
Concholepas Concholepas

Geographical variation in shell morphology of juvenile snails (Concholepas concholepas) along the physical–chemical gradient of the Chilean coast

2013 ◽  
Vol 93 (8) ◽  
pp. 2167-2176 ◽  
Author(s):  
Laura Ramajo ◽  
Ángel Baltanás ◽  
Rodrigo Torres ◽  
Patricio H. Manríquez ◽  
Alejandro Rodriguez-Navarro ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Environmental Gradients ◽  
Function Analysis ◽  
Shell Morphology ◽  
Shell Shape ◽  
Phenotypic Traits ◽  
Shell Weight ◽  
Chilean Coast ◽  
Physical Chemical ◽  
Concholepas Concholepas

Changes in phenotypic traits, such as mollusc shells, are indicative of variations in selective pressure along environmental gradients. Recently, increased sea surface temperature (SST) and ocean acidification (OA) due to increased levels of carbon dioxide in the seawater have been described as selective agents that may affect the biological processes underlying shell formation in calcifying marine organisms. The benthic snailConcholepas concholepas(Muricidae) is widely distributed along the Chilean coast, and so is naturally exposed to a strong physical–chemical latitudinal gradient. In this study, based on elliptical Fourier analysis, we assess changes in shell morphology (outlines analysis) in juvenileC. concholepascollected at northern (23°S), central (33°S) and southern (39°S) locations off the Chilean coast. Shell morphology of individuals collected in northern and central regions correspond to extreme morphotypes, which is in agreement with both the observed regional differences in the shell apex outlines, the high reclassification success of individuals (discriminant function analysis) collected in these regions, and the scaling relationship in shell weight variability among regions. However, these extreme morphotypes showed similar patterns of mineralization of calcium carbonate forms (calcite and aragonite). Geographical variability in shell shape ofC. concholepasdescribed by discriminant functions was partially explained by environmental variables (pCO2, SST). This suggests the influence of corrosive waters, such as upwelling and freshwaters penetrating into the coastal ocean, upon spatial variation in shell morphology. Changes in the proportion of calcium carbonate forms precipitated byC. concholepasacross their shells and its susceptibility to corrosive coastal waters are discussed.

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