Allometric growth patterns in hatchery-reared larvae of the catfish Lophiosilurus alexandri (Pisces: Pseudopimelodidae)

The aim of the present study was to characterize the relationships that occur between morphometric variables of larvae of Lophiosilurus alexandri Steindachner, 1876 through their allometric growth analysis. Total length, head length and body height were correlated with standard length, head height and body height, as well as eye diameter and head height with head length. The results revealed allometric positive relation during the initial development, where the b coefficient varied between 1.10 and 2.81. The variable pre-anal distance in relation to the standard length and the snout length in relation to the head length revealed an allometric negative relation, where the b coefficient was 0.85 and 0.94, respectively

Benthic habitat properties can delay settlement in an estuarine fish (Sciaenops ocellatus)

Funds were provided from the University of Texas Marine Science Institute Perry R. Bass Chair in Fisheries and Mariculture.Settlement is the last stage of high mortality in the life cycle of demersal marine fishes, making the number of larvae that successfully settle to a benthic habitat a predictor of future population size. Habitat selection is an active settlement process for coral reef fishes, however, there has been less research about settlement in other ecosystems. This study used laboratory and field experiments to examine the relationship between size and settlement over various substrates in red drum Sciaenops ocellatus, a temperate and subtropical estuarine species. In the laboratory, vertical position of fish (4.3 to 40.0 mm standard length [SL]) was recorded in the presence of sand, oyster shells, or seagrass to determine median settlement size. Median settlement size was 12.9 mm SL for seagrass, 15.8 mm SL for sand, and 20.5 mm SL for oyster shells. To determine the size at which fish settle in the wild, vertically partitioned field enclosures were used to separate individuals (5.2 to 37.3 mm SL) in the water column (>16 cm from the sediment) from those in the seagrass (Publisher PDFPeer reviewe

Frontiers in marine movement ecology: mechanisms and consequences of migration and dispersal in marine habitats

Benjamin D. Walther, Pablo Munguia, and Lee A. Fuima

Fish otolith asymmetry: Morphometry and modeling

11 pages, 8 figures, 1 tableMathematical modeling suggests that relatively large values of otolith mass asymmetry in fishes can alter acoustic functionality and may be responsible for abnormal fish behavior when subjected to weightlessness during parabolic or space flight [D.V. Lychakov, Y.T. Rebane, Otolith mass asymmetry in 18 species of fish and pigeon, J. Grav. Physiol. 11 (3) (2004) 17–34; D.V. Lychakov, Y.T. Rebane, Fish otolith mass asymmetry: morphometry and influence on acoustic functionality, Hear. Res. 201 (2005) 55–69]. The results of morphometric studies of otolith mass asymmetry suppose that the absolute value and the sign of the otolith mass asymmetry can change many times during the growth of individual fish within the range ±20% [D.V. Lychakov, Y.T. Rebane, Otolith mass asymmetry in 18 species of fish and pigeon, J. Grav. Physiol. 11 (3) (2004) 17–34; D.V. Lychakov, Y.T. Rebane, Fish otolith mass asymmetry: morphometry and influence on acoustic functionality, Hear. Res. 201 (2005) 55–69]. This implies that the adverse effects of otolith asymmetry on acoustic and vestibular functionality could change during the lifetime of an individual fish. The aims of the present article were to examine the nature of otolith mass asymmetry fluctuation and to quantify otolith mass asymmetry in a large number of teleost fishes to verify our previous measurements. A dimensionless measure of otolith mass asymmetry, χ, was calculated as the difference between the masses of the right and left paired otoliths divided by average otolith mass. Saccular otolith mass asymmetry was studied in 59 Mediterranean teleost species (395 otolith pairs), 14 Black Sea teleost species (42 otolith pairs), red drum (196 otolith pairs) and guppy (30 otolith pairs). Utricular otolith mass asymmetry was studied in carp (103 otolith pairs) and goldfish (45 otolith pairs). In accordance with our previous results the value of χ did not depend on fish size (length or mass), systematic or ecological position of the fish, or otolith growth rate. In the great majority of the fishes studied, the saccular otolith χ was small |χ| < 0.05 (or <5%). Mathematical modeling indicates that values of χ vary among individual fish, but that the value is probably stable during a fish’s lifetime.This work was partly supported by Russian RFFI 05-04-48303 Grant, Russian St. Petersburg Scientific Center 03.02 Program, Contribution 1406 of The University of Texas Marine Science Institute.Peer reviewe

Why polar gigantism and palaeozoic gigantism are not equivalent: Effects of oxygen and temperature on the body size of ectotherms

Contains fulltext : 123399.pdf (publisher's version ) (Open Access