Composition, seasonality and distribution of the Ichthyoplankton in the Lower Swan Estuary, South-western Australia

1990 ◽  
Vol 41 (4) ◽  
pp. 529 ◽  
Author(s):  
DJ Gaughan ◽  
FJ Neira ◽  
LE Beckey ◽  
IC Potter
Keyword(s):  
Western Australia ◽  
Fish Larvae ◽  
Marine Species ◽  
Late Spring ◽  
Lower Estuary ◽  
Estuary Mouth ◽  
Conical Nets ◽  
Eggs And Larvae ◽  
Larval Number

Paired conical nets (0.5 mm mesh) were used to sample ichthyoplankton at three sites in the lower Swan Estuary in each month between May 1986 and April 1987. In all, 3948 fish larvae were caught, representing 32 families and 60 species, of which 29 could be assigned species names. The Clupeidae (20.2%), Engraulididae (10.4%), Callionymidae (8.7%) and Nemipteridae (6.8%) made the greatest contributions to the total larval number, followed by the Pinguepididae (5.8%), Gobiidae (5.8%), Terapontidae (5.7%) and Monacanthidae (5.4%). The most numerous of the identified species were Engraulis australis (10.4%), Hyperlophus vittatus (8.9%), Callionymus goodladi (8.7%) and Sardinella lemuru (7.4%). The 11 most abundant of the identified species included 2 that spawn in the estuary (E. australis and Parablennius tasmanianus) and 2 that spawn at sea but are abundant as juveniles in the estuary (Pelates sexlineatus and H. vittatus). The remaining 7 species are not common as either juveniles or adults in any region of the Swan Estuary. The larvae of marine species collected just inside the estuary mouth were very similar in size to those collected a further 7.2 km upstream, indicating that they are transported rapidly through the lower estuary, presumably through tidal action. The concentrations of both eggs and larvae of all fish collectively, and the concentrations of larvae of most of the abundant identified species, peaked between late spring and midsummer (November- January).

The larval fish assemblage of the Nornalup-Walpole Estuary, a permanently open estuary on the southern coast of Western Australia

1994 ◽  
Vol 45 (7) ◽  
pp. 1193 ◽  
Author(s):  
FJ Neira ◽  
IC Potter
Keyword(s):  
Western Australia ◽  
Fish Assemblage ◽  
Larval Fish ◽  
Fish Larvae ◽  
Marine Species ◽  
Abundant Species ◽  
Entrance Channel ◽  
Southern Coast ◽  
Outer Basin

Fish larvae were sampled in the entrance channel and in the two basins of the permanently open Nornalup-Walpole Estuary, on the southern coast of Western Australia, in each month between October 1989 and September 1990. Sampling yielded a total of 39 068 larvae belonging to 36 species and 23 families, with the engraulidid Engraulis australis (56.7%) and the gobies Pseudogobius olorum (24.4%) and Favonigobius lateralis (15.0%) being the most abundant species. Most of the larvae were caught between November and March, with the concentrations of the most abundant species reaching peaks between January and March, when water temperatures had reached 21-24�C. In terms of number of larvae, the larval fish assemblage in the basins was dominated by species that spawn within the estuary, with the larvae of these species contributing ≥98.7% to the totals at the basin sites. Although the larvae of 26 marine species were caught in the entrance channel, these were either rare or absent in the basins, except for those of the terapontid Pelates sexlineatus, which were moderately abundant in the outer basin. The fact that the larvae of most of these marine species were at the preflexion stage, and that all but three of those species had never been previously recorded as either juveniles or adults within the system, indicates that they were passively transported from outside the estuary. The absence of larvae of most of the marine teleosts that are abundant in the basins of the Nornalup-Walpole Estuary parallels the situation in the nearby and seasonally closed Wilson Inlet.

Larval morphology predicts geographical dispersal range of Eastern Pacific eels

2019 ◽  
Vol 128 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Katherine E Dale ◽  
M Timothy Tinker ◽  
Rita S Mehta
Keyword(s):  
Body Shape ◽  
Phylogenetic Signal ◽  
Morphological Diversity ◽  
Marine Species ◽  
Eastern Pacific ◽  
Geographical Range ◽  
Larval Body ◽  
Adult Morphology ◽  
Adult Habitat ◽  
Eggs And Larvae

Abstract The geographical range of many marine species is strongly influenced by the dispersal potential of propagules such as eggs and larvae. Here, we investigate morphological diversity and the effect of body shape on geographical range of leptocephali, the unique, laterally compressed larvae of eels (order Anguilliformes). We used phylogenetically informed analyses to examine the morphological variation of larvae for 17 Eastern Pacific eel species from three adult habitats. We also investigated whether morphological traits of leptocephali could predict larval latitudinal range, hypothesizing that body shape may influence passive dispersal via currents. We found that no two species shared the same multivariate growth trajectories, with the size and scaling of pectoral fin length and snout-to-anus length being particularly variable. Larvae with longer relative predorsal and snout-to-anus lengths at median sizes exhibited wider larval geographical ranges. Body aspect ratio and maximum body length at metamorphosis, two traits we hypothesized to be important for passive transport, were not significant predictors of maximal larval range. We discovered an increase in phylogenetic signal over larval development as eels approach metamorphosis, potentially due to similar selective pressures between related species (such as juvenile habitat or adult morphology). Lastly, we conclude that larval body shape is probably influenced by adult habitat and adult morphology.

Turbulent mixing and mesoscale distributions of late-stage fish larvae on the NW Shelf of Western Australia

2006 ◽  
Vol 15 (1) ◽  
pp. 44-59 ◽  
Author(s):  
M. G. MEEKAN ◽  
J. H. CARLETON ◽  
C. R. STEINBERG ◽  
A. D. MCKINNON ◽  
R. BRINKMAN ◽  
...  
Keyword(s):  
Western Australia ◽  
Turbulent Mixing ◽  
Late Stage ◽  
Fish Larvae

A comparative account of the reproductive cycles of five species of marine mussels (Bivalvia: Mytilidae) in the vicinity of Fremantle, Western Australia

1967 ◽  
Vol 18 (2) ◽  
pp. 175 ◽  
Author(s):  
BR Wilson ◽  
EP Hodgkin
Keyword(s):  
Reproductive Cycle ◽  
Western Australia ◽  
Marine Species ◽  
Spawning Season ◽  
Latitudinal Distribution ◽  
Marine Mussels ◽  
Reproductive Cycles ◽  
Determining Factor ◽  
Pacific Species

Descriptions are given of the reproductive cycles of five marine species of mussels. Two of these species have a southern Australian distribution and three are tropical Indo-Pacific species or have Indo-Pacific affinities. The reproductive cycles differ significantly, each species exhibiting a characteristic breeding pattern. A distinction is drawn between the season of gametogenic activity and the much narrower season of actual spawning. In four of the species the major features of the reproductive cycle correlate with latitudinal distribution. This is interpreted as evidence supporting the role of temperature as a principal determining factor in the control of broader aspects of the reproductive cycle (i.e. duration and season of gametogenic activity). Differences in finer details of the reproductive cycles (e.g. spawning season and number of spawning peaks) appear to be controlled by unknown factors besides temperature.

scholarly journals Long-term changes of ichthyoplankton communities in an Iberian estuary are driven by varying hydrodynamic conditions

2020 ◽  
Author(s):  
M Monteiro ◽  
U M Azeiteiro ◽  
F Martinho ◽  
M A Pardal ◽  
A L Primo
Keyword(s):  
Environmental Variability ◽  
Larval Fish ◽  
Fish Larvae ◽  
Climate Change Impacts ◽  
Variable Structure ◽  
Local Environment ◽  
Strong Relationship ◽  
Marine Species ◽  
Economic Implications ◽  
Species Dominance

Abstract Ichthyoplankton assemblages are key components of estuaries worldwide, playing a vital role as nurseries for fish larvae. Nonetheless, estuaries can be highly affected by ongoing climate change. Impacts of climate variability on ichthyoplankton assemblages will have consequences for marine pelagic food webs and fish populations biology, namely recruitment. This study aims to investigate the influence of environmental variability on an interannual abundance of ichthyoplankton assemblages of the Mondego estuary (Portugal). For this, an ichthyoplankton sampling programme of 13 years (2003–2015) along six distinct sampling stations was analysed to evaluate spatial, seasonal and interannual changes of ichthyoplankton distribution over periods of wet, regular and dry conditions. The ichthyoplanktonic community was dominated by Pomatoschistus spp. across all seasons and conditions, with higher larval abundances during summer and spring. Main changes were related to species seasonality and phenology as well as an increase in the number of marine species during extreme events. The larval fish community showed a strong relationship with the regional and local environment over the study, presenting a distinct yet highly variable structure during the 2009–2013 period. Reported changes will likely trigger major changes in species dominance and abundance, with clear ecological and socio-economic implications.

Spatial and seasonal distribution of eggs and larvae of sandy sprat, Hyperlophus vittatus (Clupeidae), off south-western Australia

1996 ◽  
Vol 47 (8) ◽  
pp. 971 ◽  
Author(s):  
DJ Gaughan ◽  
WJ Fletcher ◽  
RJ Tregonning
Keyword(s):  
Continental Shelf ◽  
Western Australia ◽  
Surf Zone ◽  
Temporal Distribution ◽  
Seasonal Distribution ◽  
Spawning Season ◽  
Marine Waters ◽  
Spawning Areas ◽  
Spatio Temporal ◽  
Eggs And Larvae

Ichthyoplankton surveys were employed to determine the distribution and spawning season of Hyperlophus vittatus off south-western Australia. Eggs and larvae of H. vittatus were sampled with 500-μm-mesh bongo-nets monthly during 1992, and less regularly during 1993, close to the beach and at 5.5 and 11 km offshore in four areas within the region of the fishery. The spatio-temporal distribution and abundance of eggs indicates that H. vittatus spawns in nearshore marine waters from May to September, with a peak in June and July. Larvae were rarer and less abundant than the eggs and therefore were less reliable indicators of spawning areas and season. Samples taken along transects across the continental shelf in July of both 1993 and 1994 indicated that H. vittatus did not spawn further than 14 km from the coast. Samples taken in July 1994 just beyond the surf zone at beaches, and at corresponding sites 5.5 km offshore, at 3.7-km intervals along 150 km of coastline indicated that H. vittatus spawns throughout the distribution of the fished stock off south-westem Australia.

scholarly journals La distribución del ictioplancton está directamente relacionada con la hidrodinámica de una región y el comportamiento de desove de los adultos. En este estudio buscamos mapear las zonas de mayor ocurrencia de ictioplancton observadas en la Bahía de São Marcos, que tiene una de las mayores amplitudes de marea en la Costa Amazónica, Brasil. El ictioplancton fue recolectado mediante una técnica de arrastre horizontal en la capa superficial, utilizando una red de rodillos cónicos con malla de 300 μm acoplada a un medidor de flujo, para estimar el volumen de agua filtrada en la Bahía de São Marcos (Complexo Estuarino de São Marcos - CESM, Maranhão) . La densidad se calculó a partir de la relación entre el número total de huevos y larvas en cada muestra y el volumen de agua filtrada. Las fuentes de Ictioplancton se consideraron continuas y se organizaron para representar de forma asincrónica las condiciones de distribución. Para ello se realizó utilizando el polígono de Voronoi para determinar la forma espacial del área de operación de todos los puntos de muestreo. El uso de CESM, como lugar de desove y cría de larvas de peces, se verificó en todas las épocas del año, con mayor densidad de huevos en la época de lluvias y mayor densidad de larvas durante la época seca. La ubicación de las mayores densidades de ictioplancton varió, con las concentraciones más altas más cerca del canal sureste del CESM en la estación seca, moviéndose hacia el centro en la estación lluviosa. El canal sureste del CESM era, por tanto, un área de cría de muchas especies de peces, lo que requería una acción prioritaria para la protección del medio ambiente.

2020 ◽  
Vol 9 (10) ◽  
pp. e9229109238
Author(s):  
Rômulo de Araújo Soares ◽  
Júlio Cesar Martins Ribeiro Júnior ◽  
Paula Cilene Alves da Silveira ◽  
Raimunda Fortes Carvalho Neta ◽  
Audalio Rebelo Torres Junior
Keyword(s):  
Fish Larvae ◽  
Central Area ◽  
Spawning Behavior ◽  
Dry Period ◽  
Management Actions ◽  
Spawning Site ◽  
Sampling Points ◽  
Spatial Shape ◽  
Para Determinar ◽  
Eggs And Larvae

The occurrence of ichthyoplankton is associated to the hydrodynamics and spawning behavior of adults. In this study we aimed to detect regions of concentration of ichthyoplankton in São Marcos Bay, which has macro tidal amplitudes in Amazon Coast, Brazil. Ichthyoplankton was acquired by way of drag technique, using with 300 μm mesh. The density was obtained considering the number of eggs and larvae in filtered water. The sources of Ichthyoplankton were defined continuous and organized to denote the asynchronously the distribution conditions. To this was done using Voronoi polygon to determine the spatial shape of the region of operation of all sampling points. The use of CESM, as a spawning site and breeding fish larvae, was verified at all times of the year, with a higher density of eggs in the wet period and a higher density of larvae during the dry period. The position of the higher ichthyoplankton densities varied, considering concentrations in the area at south-east channel of the CESM in the rainless period, going to the central area in the wet period. The southeast of CESM is, therefore, a nursery for fish, requiring environmental management actions.

scholarly journals Evidence of Cnidarians sensitivity to sound after exposure to low frequency noise underwater sources

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Marta Solé ◽  
Marc Lenoir ◽  
José Manuel Fontuño ◽  
Mercè Durfort ◽  
Mike van der Schaar ◽  
...  
Keyword(s):  
Fish Larvae ◽  
Low Frequency ◽  
Noise Pollution ◽  
Marine Species ◽  
Acoustic Trauma ◽  
Sensory Epithelium ◽  
Frequency Noise ◽  
Noise Levels ◽  
Sound Sources ◽  
The Impact

Abstract Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don’t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.

Ichthyoplankton community of the Dardanelles Strait, Turkey

2017 ◽  
Vol 46 (3) ◽  
Author(s):  
İsmail Burak Daban ◽  
Ahsen Yüksek
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Teleost Fish ◽  
Dominant Species ◽  
Fish Larvae ◽  
The Other ◽  
Fish Eggs ◽  
One Year ◽  
Eggs And Larvae ◽  
Fish Eggs And Larvae

AbstractAn ichthyoplankton survey was conducted between March 2012 and February 2013 along the Anatolian coast of the Dardanelles Strait, with the aim of describing the species composition and temporal variation of fish eggs and larvae. For this purpose, monthly samples were collected at three sites using a WP-2 plankton net equipped with 500 µm mesh during a one-year period. Biodiversity indices were calculated to understand differences in biodiversity. A total of 50 teleost fish species belonging to 25 families and 7 orders were identified. The highest species richness of fish eggs was recorded in spring, whereas the highest species richness of fish larvae – in spring and summer. On the other hand, species richness of fish eggs and larvae were at a minimum in the fall. The most dominant species recorded in the Dardanelles were

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