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M. N. DiLauro

Publications and source records attributed to M. N. DiLauro.

8 recordsLinked to original sources
USGS2011

Fish species composition two second-order headwater streams the North Central Appalachians ecoregion

Fish species composition was determined for two second-order headwater streams within the North Central Appalachians ecoregion in northern Pennsylvania. The two streams were widely spaced geographically (over 193 km apart) and occurred in different drainage systems. Streams were sampled in the spring and fall over two years (1996–98) yielding similar fish assemblages. A total of five species was collected. Mottled sculpin ( Cottus bairdli ), slimy sculpin ( Cottus cognatus ), brook trout ( Salvetinus fontinalis ), and brown trout ( Salmo trutta ) were the dominant adult fishes. Two creek chubs ( Semotilus atromaculatus ) were also collected. No significant differences were found in sculpin weight, sculpin length, salmonid length, or brook trout length between streams. Paired t-tests detected eight significant seasonal differences within sites. Brook trout and mottled sculpin lengths were significantly greater in fall versus spring, while the reverse was found with slimy sculpins. Catches per unit effort were similar between the two streams, yielding 8.46 and 8.07 fish per minute of electrofishing. Both streams were very similar in faunal assemblages attributed to small, coldwater, high quality headwater streams in other regions.

Pennsylvanaia↗
USGS2001

Sperm-cell ultrastructure of North American sturgeons. IV. The pallid sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)

Sperm-cell morphology and ultrastructure in the pallid sturgeon (Scaphirhynchus albus) were examined using transmission and scanning electron microscopy. Metrics and structure were compared with similar metrics obtained from other published descriptions of sturgeon sperm cells. General morphology was found to be similar to that of sperm cells of the white (Acipenser transmontanus), lake (A. fulvescens), stellate (A. stellatus), Chinese (A. sinensis), Russian (A. gueldenstaedti colchicus), and shortnose (A. brevirostrum) sturgeons, which all shared a gradual tapering of the nuclear diameter from posterior to anterior, unlike that of the Atlantic sturgeon (A. oxyrhynchus). The sperm cell of the pallid sturgeon was similar in size to that of the Atlantic sturgeon, being only slightly larger. The sperm cell of the pallid sturgeon differed from those of other sturgeons chiefly in the acrosomal region, where the posterolateral projections (PLP) have the shape of an acute triangle and are arranged in a spiral about the longitudinal axis of the cell. The PLP were longer than those of other sturgeons, being twice the length of those of the Atlantic sturgeon and 58% longer than those of the lake sturgeon. Also, in cross section the acrosome had the shape of a hollow cone rather than the cap of an oak tree acorn, as was found in ultrastructural studies of other sturgeons. In addition, we were able to confirm that the structural arrangement of the distal centriole of the midpiece is identical with that of the proximal centriole: nine sets of microtubular triplets around the periphery of the centriole. This information is of potential use to fishery biologists, forensic biologists, zoologists, reproductive physiologists, taxonomists, evolutionary biologists, and aquaculturists.

Canadian Journal of Zoology↗
USGS1998

Growth and survival of lake sturgeon larvae fed formulated diets

We conducted a 60‐d experiment to ascertain diet‐related differences in survival and growth of larval lake sturgeon Acipenser fulvescens. We offered formulated diets to larval lake sturgeon 2 weeks after first‐feeding to find a suitable formulated diet. The five formulated diets were fed to larvae in combination with live brine shrimp Artemia sp., which served as a control. There was no diet effect ( P ≤ 0.05) on mean survival, which ranged from 67.4% to 58.3%. Lake sturgeon fed only brine shrimp were significantly greater in mean length (60.4 mm) at 68 d of age than all other treatments, and BioKyowa produced the lowest (44.2 mm) mean length. Mean weight of fish provided brine shrimp (0.74 g) was significantly greater than the weights of those fed the Tunison, Biodiet, or BioKyowa diets. There was no indication that larval lake sturgeon had consumed the formulated feeds; rather, it is likely they may have become imprinted on brine shrimp during the 2 weeks immediately following the onset of exogenous feeding.

Progressive Fish-Culturist↗
USGS1998

Renewal of voluntary feeding by wild‐caught Atlantic sturgeon juveniles in captivity

A modification of previously documented force‐feeding procedures resulted in the renewal of appetite by several wild‐caught juvenile Atlantic sturgeon Acipenser oxyrinchus. Four of four fish under controlled laboratory conditions responded positively to this technique within 1 month. These fish exhibited negative mean growth rates of −2.71 g/d before force‐feeding and gained an average of 2.61 g/d at 285 d after initiation of force‐feeding. Mean lengths, weights, and coefficients of condition ( K ) also increased after force‐feeding. This method may be useful in other situations in which the holding of juveniles or adults is necessary, such as in zoos and public aquaria.

Progressive Fish-Culturist↗
USGS1995

Influence of tank design and hydraulic loading on the behavior, growth, and metabolism of rainbow trout (Oncorhynchus mykiss)

Subadult rainbow trout ( Oncorhynchus mykiss ) stocked at 48 kg/m 3 (3 lb/ft 3 ) were subjected to treatments of tank design (rectangular plug flow, circular, and cylindrical cross flow) and water exchange rate (1·5 and 2·5 exchanges/h) to determine their effects on fish behavior, growth, and metabolism. Ambient light levels and current velocities were also measured in each of three tank sectors (upstream, middle, and downstream) to determine their relative contributions to behavioral effects. Tank design significantly affected fish orientation to current, contact time with tank surfaces, and frequency of agonistic encounters, though aggression levels were relatively low overall. Gradients in fish distribution by sector were greatest in plug-flow tanks. Effects were either modified or eliminated by increasing the water exchange rate from 1·5 to 2·5/h. Multiple-regression analysis showed the following hieararchy of independent-variable effects on fish distribution: tank type > exchange rate > aggression level > current velocity > light level. Significant effects of tank design were also observed on fish growth in terms of biomass gain (cross flow > plug flow > circular). These results were matched in metabolic studies, where both oxygen consumption and ammonia excretion were highest in circular and lowest in cross-flow tanks. Reduction (cross-flow compared with circular tanks) in oxygen consumption averaged 13·6%, ammonia excretion 17·5%. These results were also modified by an increase in water exchange rate. Tank-design effects on fish metabolism and growth may be mediated, at least partly, through changes in fish behavior.

Aquacultural Engineering↗
USGS1994

Short-term cold storage of Atlantic sturgeon sperm

Short‐term cold storage of fish sperm with oxygen, an established fisheries technique, was successfully used to preserve milt from Atlantic sturgeon ( Acipenser oxyrhynchus oxyrhynchus ). All milt samples stored for 5 d on ice and replenished daily with oxygen retained at least 80% motility and at least 99% viability. One sample exhibited 40% motility after 17 d. For management personnel involved in restoration of this rare fish, this technique offers an alternative to dependence on the simultaneous capture of ripe males and females from severely depleted stocks. It may also be used during transport prior to fertilization or cryopreservation.

Progressive Fish-Culturist↗