Ontogeny of behaviour relevant to dispersal and connectivity in the larvae of two non-reef demersal, tropical fish species

2009 ◽  
Vol 60 (3) ◽  
pp. 211 ◽  
Author(s):  
Jeffrey M. Leis ◽  
Richard F. Piola ◽  
Amanda C. Hay ◽  
Colin Wen ◽  
Kun-Ping Kan
Keyword(s):  
Depth Distribution ◽  
Size Range ◽  
Reef Fishes ◽  
Population Connectivity ◽  
Marine Fishes ◽  
Tropical Fish ◽  
Larval Behaviour ◽  
Pelagic Larvae ◽  
Geographical Scale

In demersal marine fishes, the dispersal of larvae determines the geographical scale of population connectivity, and larval behaviour may influence dispersal. Yet, little is known of the ontogeny of behaviours that can influence dispersal. The present study examined the development of these behaviours in pelagic larvae of tropical marine fishes (4–21 mm) that occupy non-reef habitats as adults: Eleutheronema tetradactylum (Polynemidae) and Leiognathus equulus (Leiognathidae). In the laboratory, critical speed (Ucrit) increased from 3 to 34 cm s–1 at 1.3–1.7 cm s–1 per mm of size, with the fastest larvae up to 50% faster. In situ speed increased from 4 to 25 cm s–1 at 0.7–2.2 cm s–1 per mm, and was 10–14 body length s–1 (60–90% of Ucrit). Endurance increased from 0 to >40 km at 2.4–4.7 km per mm. In the sea, orientation precision did not change ontogenetically, both species tended to swim in loops, and neither significant overall directionality nor ontogenetic change in orientation was present. Larval orientation of these non-reef species was less precise than that of reef fishes. The two species differed in depth distribution, and one ascended ontogenetically. These behaviours can potentially influence dispersal outcomes over the full size range of these larvae.

Nanocomposite cellulose fabrics with in situ generated silver nanoparticles by bioreduction method

2020 ◽  
pp. 152808372092473 ◽  
Author(s):  
Suchart Siengchin ◽  
Pawinee Boonyasopon ◽  
Vajja Sadanand ◽  
Anumakonda Varada Rajulu
Keyword(s):  
Silver Nanoparticles ◽  
Size Range ◽  
Low Cost ◽  
Aqueous Dispersion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Bed Materials ◽  
Cellulose Fabrics

In the present work, nanocomposite cellulose fabrics with in situ generated silver nanoparticles were prepared by bioreduction method employing aqueous dispersion of low-cost natural turmeric powder as a reducing agent and different concentrated aqueous AgNO3 as source solutions. The prepared nanocomposite cellulose fabrics were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and antibacterial tests. The nanocomposite cellulose fabrics had roughly spherical silver nanoparticles in the size range of 41–130 nm with an overall average of 78 nm. The X-ray analysis indicated the generation of both silver nanoparticles and Ag2O nanoparticles in the nanocomposite cellulose fabrics. The nanocomposite cellulose fabrics retained the generated AgNPs even after repeated detergent washings. The prepared nanocomposite cellulose fabrics exhibited excellent antibacterial activity against both the Gram-negative and Gram-positive bacteria and hence can be considered as antibacterial hospital-bed materials, apparels, etc.

Nonintrusive Video Technique for in Situ Sizing of Coral Reef Fishes

Copeia ◽  
1999 ◽  
Vol 1999 (3) ◽  
pp. 789 ◽  
Author(s):  
Ronald P. Pfister ◽  
Denis Goulet
Keyword(s):  
Coral Reef ◽  
Reef Fishes ◽  
Coral Reef Fishes

scholarly journals Red fluorescence increases with depth in reef fishes, supporting a visual function, not UV protection

2014 ◽  
Vol 281 (1790) ◽  
pp. 20141211 ◽  
Author(s):  
Melissa G. Meadows ◽  
Nils Anthes ◽  
Sandra Dangelmayer ◽  
Magdy A. Alwany ◽  
Tobias Gerlach ◽  
...  
Keyword(s):  
Light Emission ◽  
Reef Fishes ◽  
Marine Fishes ◽  
Fluorescent Light ◽  
Red Fluorescence ◽  
Visual Contrast ◽  
Uv Irradiance ◽  
Reef Fish Species ◽  
Nm Range

Why do some marine fishes exhibit striking patterns of natural red fluorescence? In this study, we contrast two non-exclusive hypotheses: (i) that UV absorption by fluorescent pigments offers significant photoprotection in shallow water, where UV irradiance is strongest; and (ii) that red fluorescence enhances visual contrast at depths below −10 m, where most light in the ‘red’ 600–700 nm range has been absorbed. Whereas the photoprotection hypothesis predicts fluorescence to be stronger near the surface and weaker in deeper water, the visual contrast hypothesis predicts the opposite. We used fluorometry to measure red fluorescence brightness in vivo in individuals belonging to eight common small reef fish species with conspicuously red fluorescent eyes. Fluorescence was significantly brighter in specimens from the −20 m sites than in those from −5 m sites in six out of eight species. No difference was found in the remaining two. Our results support the visual contrast hypothesis. We discuss the possible roles fluorescence may play in fish visual ecology and highlight the possibility that fluorescent light emission from the eyes in particular may be used to detect cryptic prey.

Elasmobranch fishes from the Viséan of East Kirkton, West Lothian, Scotland

1993 ◽  
Vol 84 (3-4) ◽  
pp. 329-330 ◽  
Author(s):  
Roberta L. Paton
Keyword(s):  
Fresh Water ◽  
Oil Shale ◽  
Size Range ◽  
Lower Carboniferous ◽  
To Come ◽  
Elasmobranch Fishes

ABSTRACTThirteen fragments of fossil elasmobranchs can be identified with certainty from East Kirkton. Those collected in situ range from Units 32 to 37. The remains appear to come from two different families of sharks: spines which show features typical of the Lower Carboniferous hybodont Tristychius arcuatus Agassiz; teeth from a xenacanth which fall within the size range of those found in the Lower Carboniferous xenacanth Diplodoselache woodi Dick. Both these genera are found in other Oil-Shale assemblages in the Lothians. These rare shark fossils reinforce the evidence that the East Kirkton Limestone was fresh water in origin.

Quantifying connectivity uncertainty arising from circulation modelling inaccuracy.

2020 ◽  
Author(s):  
Elise Vissenaekens ◽  
Katell Guizien
Keyword(s):  
Root Mean Square ◽  
Flow Speed ◽  
Population Connectivity ◽  
Mean Square ◽  
Statistical Parameters ◽  
Ocean Modelling ◽  
Gulf Of Lion ◽  
Study Population ◽  
In Situ Observations

<p>Ocean modelling has become an increasingly important tool to study population connectivity and is our only tool to anticipate changes in dispersal routes in future climates. To estimate the uncertainties in model predictions, a comparison was made between the simulated currents and in situ observations in the Gulf of Lion over the period of 2009-2013. The uncertainties in Eulerian current values were described using several statistical parameters, like the bias, the root mean square (RMSE), the naturalised root mean square (NRMSE), the Hannah and Heinold parameter (HH) and the correlation. Another parameter that was introduced was the correctness, which states the percentage of time the model was deemed “correct”, based on low HH values (<75%) and high correlation (>0.25). So far, the model simulated the flow speed correctly 60-70% of the time and the relative deviation between observed and simulated flow speed was about 10%. Furthermore, ensembles of Lagrangian tracks were simulated accounting for uncertainties in Eulerian flow speed. These uncertainties were either correlated to speed values or chosen according to their statistical distribution. The Lagrangian tracks were analysed to construct connectivity matrices with and without these Eulerian uncertainties. Resulting deviation in retention and larval transfer arising from flow speed uncertainty were quantified.</p>

Sign in / Sign up

Export Citation Format

Share Document