Neustonic distribution of decapod planktonic stages and competence of brachyuran megalopae in coastal waters

2007 ◽  
Vol 58 (6) ◽  
pp. 519 ◽  
Author(s):  
Fabiana T. Moreira ◽  
Joseph Harari ◽  
Augusto A. V. Flores
Keyword(s):  
Vertical Migration ◽  
Coastal Waters ◽  
Marine Invertebrates ◽  
Larval Supply ◽  
Vertical Movements ◽  
Larval Stages ◽  
Intertidal Crab ◽  
In Captivity ◽  
Near Shore ◽  
Convergence Zones

Settlement rate may not reflect larval supply to coastal waters in different marine invertebrates and demersal fishes. The importance of near-shore oceanography and behaviour of late larval stages may be underestimated. The present study conducted neustonic sampling over station grids and along full-length transects at two embayments in south-eastern Brazil to (1) compare diurnal and nocturnal occurrence of most frequent decapod stages to assess their vertical movements, (2) describe the formation of larval patches and (3) measure competence of crab megalopae according to their distance to recruitment grounds. Several shrimp species apparently undergo a diel vertical migration, swimming crab megalopae showed no vertical movements and megalopae of the intertidal crab Pachygrapsus transversus revealed a reversed vertical migration. During the day, crab megalopae aggregated in convergence zones just below surface slicks. These larvae consisted of advanced, pre-moult stages, at both mid-bay and near-shore patches. Competence, measured as the time to metamorphosis in captivity, was similar between larval patches within each taxon. Yet, subtidal portunids moulted faster to juveniles than intertidal grapsids, possibly because they were closer to settlement grounds. Megalopae of Pachygrapsus from benthic collectors moulted faster than those from bay areas. These results suggest that alternative vertical migration patterns of late megalopae favour onshore transport, and actual competence takes place very close to suitable substrates, where larvae may remain for days before settlement. Lack of correlation between larval supply and settlement for Pachygrapsus suggests that biological processes, besides onshore transport, may play an important role in determining settlement success of coastal crabs.

scholarly journals On the generation of internal waves by river plumes in subcritical initial conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Mendes ◽  
J. C. B. da Silva ◽  
J. M. Magalhaes ◽  
B. St-Denis ◽  
D. Bourgault ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Internal Waves ◽  
Coastal Waters ◽  
Initial Conditions ◽  
Spatial Scales ◽  
River Plumes ◽  
Wide Range ◽  
Near Shore ◽  
Generation Mechanisms ◽  
Douro River

AbstractInternal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s−1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.

scholarly journals Thermal tolerance of the zoea I stage of four Neotropical crab species (Crustacea: Decapoda)

2018 ◽  
Vol 35 ◽  
pp. 1-5
Author(s):  
Adriana P. Rebolledo ◽  
Rachel Collin
Keyword(s):  
Thermal Tolerance ◽  
Elevated Temperatures ◽  
Marine Invertebrates ◽  
Negative Impact ◽  
Larval Survival ◽  
Crab Species ◽  
Marine Habitat ◽  
Mangrove Species ◽  
Larval Stages ◽  
Carry Over

. Although larval stages are often considered particularly vulnerable to stressors, for many marine invertebrates studies of thermal tolerance have focused on adults. Here we determined the upper thermal limit (LT50) of the zoea I of four Caribbean crab species (Macrocoelomatrispinosum, Aratuspisonii, Armasesricordi, and Minucarapax) and compared their thermal tolerance over time and among species. The zoea from the subtidal species M.trispinosum and tree climbing mangrove species A.pisonii had a lower thermal tolerance, 35 and 38.5 °C respectively, than did the semiterrestrial A.ricordi and M.rapax. In all four species tested, the estimates of thermal tolerance depend on the duration of exposure to elevated temperatures. Longer exposures to thermal stress produce lower estimates of LT50, which decreased by ~1 °C from a two- to a six-hour exposure. Crab embryos develop on the abdomen of the mother until the larvae are ready to hatch. Therefore, the thermal tolerances of the embryos which need to coincide with the environmental conditions experienced by the adult stage, may carry over into the early zoea stage. Our results suggest that semiterrestrial species, in which embryos may need to withstand higher temperatures than embryos of subtidal species also produce larvae with higher thermal tolerances. Over the short term, the larvae of these tropical crab species can withstand significantly higher temperatures than those experienced in their marine habitat. Longer term rearing studies are necessary to determine the temperature at which chronic exposure has a negative impact on embryonic and larval survival.

The contrasting hatching patterns and larval growth of two sympatric clingfishes inferred by otolith microstructure analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 157 ◽  
Author(s):  
Jorge E. Contreras ◽  
Mauricio F. Landaeta ◽  
Guido Plaza ◽  
F. Patricio Ojeda ◽  
Claudia A. Bustos
Keyword(s):  
Coastal Waters ◽  
Larval Growth ◽  
Microstructure Analysis ◽  
Larval Abundance ◽  
Otolith Microstructure ◽  
Austral Spring ◽  
Lunar Periodicity ◽  
Central Chile ◽  
Near Shore ◽  
Otolith Microstructure Analysis

Larval abundance, age, growth and hatching patterns of two sympatric clingfishes, Gobiesox marmoratus and Sicyases sanguineus (Pisces, Gobiesocidae), were estimated by using otolith microstructure analysis and compared on the basis of collections performed during the austral spring in 2010 off the coast of central Chile. G. marmoratus larvae were more abundant than S. sanguineus larvae during the study period. For both species, the sagittae deposited micro-increments during embryonic development (before hatching) and a hatch mark was observable in all examined otoliths. The sagittae otoliths of G. marmoratus grew in radius, perimeter and area faster than did the otoliths of S. sanguineus. Both species showed significant (P < 0.05) differences in larval growth and lunar periodicity of the hatching events. G. marmoratus hatched at smaller sizes (2.6 mm) mainly during the first-quarter moon and the larvae grew at rates of 0.24 ± 0.01 mm day–1. S. sanguineus hatched as larger larvae (>3 mm) during the first-quarter and full moons and grew at slower rates (0.14 ± 0.01 mm day–1) during the initial 25 days. The high abundance of larval clingfish in near-shore waters, temporal decoupling among the hatching events, and the different growth rates may be tactics to increase self-recruitment in coastal waters.

Copper Toxicity to Larval Stages of Three Marine Invertebrates and Copper Complexation Capacity in San Diego Bay, California

2005 ◽  
Vol 39 (6) ◽  
pp. 1542-1546 ◽  
Author(s):  
Ignacio Rivera-Duarte ◽  
Gunther Rosen ◽  
David Lapota ◽  
David B. Chadwick ◽  
Lora Kear-Padilla ◽  
...  
Keyword(s):  
San Diego ◽  
Marine Invertebrates ◽  
Copper Toxicity ◽  
Complexation Capacity ◽  
Larval Stages ◽  
Copper Complexation ◽  
San Diego Bay

scholarly journals RESONANCES OF COASTAL WATERS BETWEEN PERTH AND GERALDTON (WESTERN AUSTRALIA)

1980 ◽  
Vol 1 (17) ◽  
pp. 16 ◽  
Author(s):  
H. Allison ◽  
A. Grassia ◽  
R. Litchfield
Keyword(s):  
Spectral Analysis ◽  
Coastal Waters ◽  
Statistical Estimation ◽  
Model Comparison ◽  
Two Dimensional ◽  
Resonance Frequencies ◽  
Sea Level Oscillations ◽  
Near Shore ◽  
Quality Factor Q ◽  
Western Australian

Sea-level oscillations along the Western Australian coast, with periods in the range of 20-40 mins, have considerably greater amplitudes between Perth and Geraldton than at other locations along the coastline. It is shown that amplification of these oscillations is due to resonance in the near shore basin formed by the shore and a submerged reef-chain parallel to and 5 km from the shore. The rigorous analytical solution for the resonance frequencies is obtained for the two-dimensional hydrodynamic model. Comparison with results from spectral analysis of recorded oscillations indicates a satisfactorily agreement with the theory. Statistical estimation of damping of the observed oscillations indicates that the predominant resonance in the first mode is sharp, having the quality factor Q=10.

An evaluation of light-mediated vertical migration of fish based on hydroacoustic analysis of the diel vertical movements of rainbow smelt (Osmerus mordax)

1995 ◽  
Vol 52 (3) ◽  
pp. 504-511 ◽  
Author(s):  
A. R. Appenzeller ◽  
W. C. Leggett
Keyword(s):  
Vertical Migration ◽  
Strong Relationship ◽  
Fish Population ◽  
Osmerus Mordax ◽  
Ambient Light ◽  
Rainbow Smelt ◽  
Vertical Movements ◽  
Light Levels ◽  
Vertical Distributions ◽  
Lower Light

We used hydroacoustics to examine diel changes in the vertical distributions of rainbow smelt, Osmerus mordax, in Lake Memphremagog, Quebec/Vermont. Our objective was to evaluate hypotheses linking diel vertical movements of fish with light levels. Smelt distributions were also monitored from June through October (1988 and 1990) to evaluate seasonal changes in their behavior. A strong relationship (r2 = 0.83) between ambient light intensities and the upper fish layer in the water column was observed. Fish depth was also related to the depth of the thermocline during the night and when surface water temperatures were > 18 °C. The most characteristic feature was the strong avoidance of light levels > 0.1 μW/cm2. However, we found considerable variation in lower light levels experienced by the whole fish population. The results suggest that existing models of anti-predation behavior relating light and fish depth are consistent, with some limitations, with patterns of diel vertical migration in rainbow smelt.

scholarly journals The Larvae of the Genus Porcellana (Crustacea Decapoda) and Related Forms

1943 ◽  
Vol 25 (4) ◽  
pp. 721-737 ◽  
Author(s):  
Marie V. Lebour
Keyword(s):  
Red Sea ◽  
Coastal Waters ◽  
Larval Stages ◽  
Petrolisthes Armatus ◽  
Decapod Larvae

Although the larva of Porcellana is one of the earliest known decapod larvae and at a later date the different stages of P. longicornis were well described by Sars (1889), there is yet much that is unknown. Few larvae have been actually hatched from the egg and in no case has the number of larval stages been definitely ascertained. In order to fill in some of the gaps in our knowledge a detailed study of the two common Plymouth species was begun (P. longicornis and P. platycheles). Unfortunately, war conditions made it difficult to obtain material and many specimens were lost as the result of air-raids; it was therefore not until the summer of 1942 that the work could be finished.It is now possible to distinguish between the two species in all stages. Both have been hatched from the egg, larvae from the plankton have moulted and the post-larvae have been obtained from the last larvae. A comparison with Gurney's (1938a) notes on the species from the Red Sea and his general comments on the larvae of the genus and its relatives (1942) is of much use. These, with the first larvae of Petrolisthes armatus hatched by myself at Bermuda and certain larvae described by other workers, have made it possible to make some progress in the elucidation of the relationships of the larvae.Porcellana longicornis and P. platycheles are both common at Plymouth; but whereas the latter is confined to coastal waters and lives between tidemarks and down to about 3 fathoms, the former has a much wider range and although occurring withP. platycheles between tidemarks extends to well beyond the Eddystone grounds.

Comparative zinc and lead toxicity tests with Arctic marine invertebrates and implications for toxicant discharges

Polar Record ◽  
1993 ◽  
Vol 29 (168) ◽  
pp. 45-54 ◽  
Author(s):  
Peter M. Chapman ◽  
Cathy McPherson
Keyword(s):  
Literature Review ◽  
Marine Invertebrates ◽  
Lead Toxicity ◽  
Temperature Tolerance ◽  
The Arctic ◽  
Toxicity Tests ◽  
Test Conditions ◽  
Near Shore ◽  
Cornwallis Island ◽  
Point Source Discharges

ABSTRACTEpontic and benthic amphipods (Onisimus litoralis, Onisimus juveniles, Gammarus setosus, Anonyx nugax, and A. makarovi) and a pelagic mysid (Mysis oculatus) were collected under ice at Little Cornwallis Island, Northwest Territories, Canada. They were exposed, on site, to dissolved zinc and lead to determine lethal concentrations (LC50s). Incidental information was obtained on salinity and temperature tolerance. Subsequent testing of a temperate amphipod and oyster larvae exposed to the two metals provided comparative data to augment a literature review. The Arctic invertebrates were surprisingly insensitive under all test conditions. The implications for Arctic developments, particularly those involving near-shore, point-source discharges, are discussed and recommendations are made for effectively expanding a presently depauperate Arctic marine toxicity database.

External changes in embryonic and larval development of Odontophrynus cordobae Martino et Sinsch, 2002 (Anura: Cycloramphidae)

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Pablo Grenat ◽  
Lucio Zavala Gallo ◽  
Nancy Salas ◽  
Adolfo Martino
Keyword(s):  
Larval Development ◽  
Body Mass ◽  
Related Species ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Larval Form ◽  
Larval Stages ◽  
In Captivity ◽  
Mass Increment ◽  
Embryonic And Larval Development

AbstractWe provide the first description of development for a species belonging to Odontophrynus genus by describing all external changes of embryonic and larval stages for Odontophrynus cordobae. External morphological changes through development were analyzed on specimens bred in captivity. Embryonic and larval development, from fertilization to metamorphosis, was completed in 62 days and 46 stages were defined. We split the staging series into ten developmental groups: fertilization (stages 1 and 2); segmentation (stages 3–9); gastrulation (stages 10–12); neurulation (stages 13–16); elongation (stages 17–19); external gill larva (stages 20–24); internal gill larva (stage 25); pre-metamorphosis (stages 26–41); pro-metamorphosis (stage 42); metamorphic climax (stages 43–46). Marked increases in total length were evidenced during elongation and during stage 25, when the tadpole begins to feed. Stage 25 was the longest one (8 days) and it was related to organs rearrangement, morphological progression and body mass increment typical of free life larval form. Similar studies on related species are needed to compare different developmental stages at different taxonomic levels.

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