William J. Poly

Nongenetic Variation, Genetic-Environmental Interactions and Altered Gene Expression. I. Temperature, Photoperiod, Diet, pH and Sex-Related Effects

The use of protein electrophoretic data for determining the relationships among species or populations is widespread and generally accepted. However, many confounding factors may alter the results of an electrophoretic study in such a way as to allow erroneous conclusions to be drawn in taxonomic, systematic or population studies. Such variables as temperature, photoperiod, salinity, pH and diet have been shown to influence enzymes and proteins both quantitatively and qualitatively. Production of distinct cold and warm isozymes or seasonal isozymes have been found in a variety of organisms. The factors that are or may be responsible for the appearance of these isozymes is discussed. Most studies that have demonstrated some apparent form of environmentally induced genetic expression have not determined that mechanisms responsible. However, proteolytic modification has been shown to produce seasonal isozymes of fructose 1,6-bisphosphatase in rabbit liver and may account for other seasonal isozymes. Acclimating organisms to various conditions may actually allow detection of cryptic genetic variation and provide valuable data. There are many aspects to consider in designing acclimation experiments, and the conditions used will vary according to the aim of the research. Polyploidy may contribute to the genesis of environmentally regulated isozymes. A review of this literature follows with additional hypotheses and conclusions. Recommendations are given for the resolution of real and potential problems.

Design and evaluation of a translocation strategy for the fringed darter (Etheostoma crossopterum) in Illinois

The fringed darter (Etheostoma crossopterum) was introduced into two streams where neither the fringed darter nor any other species of the same subgenus occur but that otherwise have suitable habitat. Darters were collected from two streams in the Cache River basin, and a combination of darters from each source stream were moved to the receiving streams, which also were in the headwaters of the Cache River basin (20 males and 40 females to each). Darters were moved in late March 2001 at the beginning of their reproductive season, which continues for approximately 2 months. Fringed darter nests were present within 3 days at both introduction sites and nests were found thereafter until late May at which time searching for nests was terminated. Twenty-five nests were found in 2001 compared with 168 nests in 2002. A total of 8714 eggs were counted in 22 nests during 2001 with a mean of 413 eggs per nest (n=19 nests). In September 2001 and 2002, surveys for juveniles and adults indicated successful recruitment in both streams. Mean size of juvenile darters differed significantly between the two introduction sites in 2001. The design of this study allowed for a rapid, initial assessment of the translocations, aspects of which appeared successful. Moving fishes at the beginning of their reproductive season could increase the chance of successful reproduction and eventual establishment. The protocol for translocation of fringed darters might be applicable to other similar and endangered darters such as Barrens (Etheostoma forbesi), relict (E. chienense), and duskytail darters (E. percnurum). Sampling was conducted in other areas of the Cache River basin in search of additional populations of fringed darters. An updated account is given of the distribution of the fringed darter in Illinois.

Nontroglobitic Fishes in Bruffey-Hills Creek Cave, West Virginia, and other Caves Worldwide

Six species of fishes were tagged and released in September and November 1995 and on five dates between November 1998 and October 1999 inside Bruffey-Hills Creek Cave. Most of the tagged fishes were creek chub, Semotilus atromaculatus, and green sunfish, Lepomis cyanellus. The overall recapture rate was 2.6% as only three of 117 fishes were recaptured. Forty-nine days was the longest time of residence by two L. cyanellus and one S. atromaculatus, and movement of 83.4 m was observed only for the creek chub. Tag loss was confirmed as one factor in the low recapture rate. Nine species of fishes were collected in the cave, including Phoxinus oreas and Pimephales promelas, two species never collected in a cave. Most of the fishes were pigmented normally, but many creek chubs were depigmented and appeared white or pigmentless when first observed in the cave stream. Four species, Phoxinus oreas, Pimephales promelas, Ameiurus nebulosus, and Lepomis macrochirus, were collected for the first time in Bruffey-Hills Creek Cave and in the Bruffey and Hills creeks drainage. Although data from this study did not shed light on residence time of fishes in the cave, the consistent occurrence of epigean fishes in this cave was shown. A list of epigean fishes from caves worldwide was included along with a discussion of aspects of the ecology of epigean fishes in caves and of evolution of troglobitic fishes.

Predation on Horsehair Worms (Phylum Nematomorpha)

ABSTRACT Field observations revealed cases of predation on horsehair worms by brown trout (Salmo trutta) in Maryland and Minnesota, a rock bass (Ambloplites rupestris) in Kentucky, and a crayfish in Wisconsin. Some fish contained more than one worm and may have consumed reproductive aggregations. In laboratory feeding trials with Gordius robustus, most individuals of several fish species either ignored the horsehair worms or rejected them after taking them into their mouths briefly, but a green sunfish (Lepomis cyanellus) consumed both individual worms and a compact ball of 18 worms. A literature review yielded cases of predation on horsehair worms by at least 12 fish species. Horsehair worms usually were only a trace component of the diet, but some individual fish had eaten multiple worms.

Nongenetic variation, genetic-environmental interactions and altered gene expression. III. Prosttranslational modifications

The use of protein electrophoretic data for determining the relationships among species or populations is widespread and generally accepted. However, posttranslational modifications have been discovered in many of the commonly analyzed proteins and enzymes. Posttranslational modifications often alter the electrophoretic mobility of the modified enzyme or protein. Because posttranslational modifications may affect only a fraction of the total enzyme or protein, an additional staining band often appears on gels as a result, and this may confound interpretations. Deamidation, acteylation, proteolytic modification, and oxidation of sulfhydryl groups are modifications that often result in an electrophoretic mobility shift. Sialic acid-induced heterogeneity has been documented for many enzymes, but neuraminidase treatment can often remove sialic acids and produce gel patterns that are easier to interpret. In some cases, ontogenetic and tissue-specific expression may be due to posttranslational modifications rather than gene control and restricted expression, respectively. Methods of preventing, detecting and eliminating posttranslational modifications are discussed. Some posttranslational modifications may be useful for detecting cryptic genetic polymorphisms.

Nongenetic variation, genetic-environmental interactions and altered gene expression. II. Disease, parasite and pollution effects.

The use of protein electrophoretic data for determining the relationships among species or populations is widespread and generally accepted. However, there are many confounding factors that may alter the results of an electrophoretic study and may possibly allow erroneous conclusions to be drawn in taxonomic, systematic or population studies. Measured enzyme activities can also be affected significantly. Parasites, disease and pollution can affect levels of enzyme activity, and electrophoretic results can be affected both quantitatively and qualitatively. Blood serum is particularly vulnerable to variation to variation due to disease, pollution or parasites because damaged tissues may release tissue-specific enzymes into the bloodstream. Capture, handling, chemical treatments, bacteria, natural toxins and consumed food may also contribute to variation. Potential pollution impacts at specimen collection sites should be investigated, and study organisms should be inspected and/or treated for detection and elimination of parasites and disease.

Range Expansion of Golden Crayfish, Orconectes luteus, in the Mississippi River

ABSTRACT Golden crayfish (Orconectes luteus) specimens were collected in the Mississippi River at Grand Tower, Jackson County, Illinois in September and October 1999. This locality is the most eastern on record for the species and the most southern in Illinois. The high stream order habitat from which these crayfish were collected is generally not consistent habitat compared with preferred smaller order stream habitats used in other parts of the species range. Previous collections of O. placidus from the Mississippi River may in fact be O. luteus.

New State, Host, and Distribution Records of the Fish Ectoparasite, Argulus (Branchiura), From Illinois (U.S.a.)

Argulus americanus, A. flavescens, A. lepidostei, and A. japonicus are reported from Illinois for the first time. Gizzard shad (Dorosoma cepedianum) is a new host record for A. japonicus, bigmouth buffalo (Ictiobus cyprinellus) is a new host record for A. catostomi, and black crappie (Pomoxis nigromaculatus) is a new host record for A. stizostethii. Eight species, A. americanus, A. appendiculosus, A. catostomi, A. flavescens, A. japonicus, A. lepidostei, A. mississippiensis, and A. stizostethii, have been recorded from 13 Illinois fish species. Ciliated protozoans (Epistylis or Opercularia) were observed on four Argulus spp., and crustacean shell disease was observed on five species.

HOST AND LOCALITY RECORDS OF THE FISH ECTOPARASITE, ARGULUS (BRANCHIURA), FROM OHIO (U.S.A.)

Argulus flavescens and A. appendiculosus were collected from five fish species in two major Ohio river basins during August-October, 1994. The golden redhorse, Moxostoma erythrurum, is a new host record for Argulus. The 1994 records as well as past host and distribution records of Argulus in Ohio and Lake Erie (U.S. and Canadian waters) have been compiled. Six species, A. flavescens, A. appendiculosus, A. lepidostei, A. stizostethii, A. americanus, and A. catostomi have been recorded from 15 Ohio fish species.

Trimusculotrema schwartzi n. sp. (Monogenea: Capsalidae) from the skin of the stingray Dasyatis zugei (Elasmobranchii: Dasyatidae) off Hong Kong, China.

Trimusculotrema schwartzi n. sp. (Capsalidae) is described from the skin of the stingray Dasyatis zugei (Elasmobranchii: Rajiformes: Dasyatidae) off Hong Kong, China. Only three other species have been placed in the genus Trimusculotrema: T.xa0micracantha (Euzet & Maillard, 1967), T.xa0leucanthemum (Euzet & Maillard, 1967), and T.xa0uarnaki Whittington & Barton, 1990. T.xa0schwartzi n. sp. may be differentiated from all known species of Trimusculotrema by the length of the anterior hamuli and by the absence of pigment shields over the eye-spots. Its occurrence on a stingray off China represents a northern extension of the geographical range of Trimusculotrema.