Wilmer A. Rogers

Chemiluminescence by peripheral blood phagocytes from channel catfish: Function of opson in and temperature

The ability of the peripheral blood phagocytes from channel catfish, Ictalurus punctatus, to produce chemiluminescence (CL) following ingestion of the enteric pathogen Edwardsiella ictaluri was evaluated under a variety of opsonic and temperature conditions. The CL response was influenced by the concentration of immune serum used to opsonize the bacteria as well as the presence of nonspecific, heat labile opsonins. Peak light emissions were diminished and the time to peak response was increased with a reduction in temperature. Temperature-mediated changes in CL activity was accompanied by a corresponding change in intracellular killing. The addition of the metabolic inhibitors superoxide dismutase or sodium azide resulted in a reduction in CL and intracellular killing.

Survival of Caught and Released Largemouth Bass after Containment in Live Wells

Abstract Survival of angled largemouth bass Micropterus salmoides held in live wells for 3–9 h, with and without a water conditioner, was compared to largemouth bass released within 30 min (immediate release) of capture. The study was set up to simulate conditions that may occur during a largemouth bass tournament. Simulated tournaments were held in August, November, February, May, and July. Survival of prerelease and postrelease fish was higher when water temperatures were cool during fall and winter. Survival of largemouth bass released within 30 min was 98.9%, which was higher (P < 0.01) than survival of fish held in live wells without a water conditioner (90.8%). Fish held for 3–9 h in live wells with a water conditioner had a 96.5% survival, which was higher (P < 0.05) than survival for those held in unconditioned water. Largemouth bass caught in July had higher mortality than fish caught in November, February, or May. Indications are that addition of a water conditioner to live wells enhances surviv...

Changes in Total Protein and Transaminase Activities of Grass Carp Exposed to Diquat

Abstract Total protein in plasma and muscle of grass carp Ctenopharyngodon idella was significantly lower (P < 0.05) in fish exposed to 53.0 mg diquat/L than in fish exposed to 2.0 mg diquat/L. Generally, total protein in fish exposed to 2.0 mg diquat/L was not significantly different from total protein in control fish (0.0 mg diquat/L) throughout 168 h of exposure. Aspartate aminotransferase (=glutamic-oxaloacetic transaminase; GOT) activities increased significantly in plasma, muscle, and liver of fish exposed to 53.0 mg diquat/L. However, in fish exposed to 2.0 mg diquat/L, plasma and liver GOT decreased significantly. Alanine aminotransferase (=glutamicpyruvic transaminase; GPT) activities increased significantly in plasma and liver of fish exposed to 53.0 mg diquat/L, whereas there was no change in fish exposed to 2.0 mg diquat/L.

Effect of cooking on residues of ormetoprim and sulfadimethoxine in the muscle of channel catfish

Channel catfish Ictalurus punctatus were fed Romet medicated feed at doses of 25, 50, and 100 mg Romet per kg of fish daily for 5 d. To keep Romet concentration high enough for evaluation of cooking effects, fillets were sampled without the 3 d withdrawal period required by the US Food and Drug Administration. Concentrations of ormetoprim (OMP) and sulfadimethoxine (SDM), the antibiotics in Romet, were determined by a high-pressure liquid chromatography method in fillets before and after cooking. Fillets were cooked by one of four methods: smoked at 160–200 °C, baked at 190 °C, fried in canola oil at 190 °C, and injected with a mixture of 6% polyphosphate solution, frozen for 4 weeks, and then fried in vegetable oil at 190 °C. The average OMP concentrations in cooked tissue were 0.23, 0.66, and 1.22 μ/g dry basis (db) and SDM concentrations were 2.64, 2.73, and 3.74 μg/g db for fish dosed with Romet at levels of 25, 50, and 100 mg/kg, respectively. Cooking caused an average 54.0% reduction of OMP and 46.1% reduction of SDM from raw fillet of fish. Cooking significantly reduces both OMP and SDM residues in fillets and provides an additional margin of safety for consumers. Results for the four cooking methods were not statistically different.

Feed-related anemia in cultured channel catfish (Ictalurus punctatus)

Abstract During 1983, 70 cases of severe anemia and death in cultured channel catfish occurred in Alabama and Georgia. These cases could not be associated consistently with pathogens or the pond environment. Diets fed to the affected fish contained no significant levels of pesticides, heavy metals, peroxides (oxidized lipids) or known mycotoxins that could cause the anemia. Experimental induction of severe anemia in cage-held channel catfish resulted in hematocrits as low as 1–9%. Average hematocrit of the affected population was 25.8% compared to an average of 37% for control fish. Hemoglobin concentration and erythrocyte counts were lower in affected fish than in controls, and clotting time of the blood was longer in test fish. The mortality during the study was 9% in the test fish compared to 0.05% in the controls.

Studies on Dactylogyrinae (Monogenea) with descriptions of 24 new species of Dactylogyrus, 5 new species of Pellucidhaptor, and the proposal of Aplodiscus gen. n.

Thirty new and 29 previously described species of Dactylogyrinae are reported from fishes of the southeastern U. S. 1T The new species and their hosts are: Aplodiscus nasalis, gen. et sp. n. from Hypentelium etowanum (Jordan); Dactylogyrus acicularis sp. n. from Moxostoma poecilurum (Jordan); D. arcus sp. n., D. cursitans sp. n., D. lepidus sp. n., D. luxili sp. n., and D. manicatus sp. n. from Notropis chrysocephalus isolepis Hubbs and Brown; D. argenteus sp. n. from Notropis shumardi (Girard); D. caudoluminis sp. n. from Notropis maculatus (Hay); D. cheloideus sp. n. from Rhinichthys atratulus (Hermann); D. crucis sp. n. from Notropis bellus (Hay); D. ericymbae sp. n. and D. julieae sp. n. from Ericymba buccata Cope; D. fungulus sp. n. from Notropis callistius (Jordan); D. hemitremiae sp. n. from Hemitremia flammae (Jordan and Gilbert); D. limulus sp. n. and D. reciprocus sp. n. from Hybopsis bellica (Girard); D. magnus sp. n. from Hybopsis storeriana (Kirtland); D. opsopoeodi sp. n. from Opsopoeodus emiliae Hay; D. ornatus sp. n. from Notropis baileyi Suttkus and Raney; D. parvaccessorius sp. n. from Hybopsis herperi (Fowler), D. plegadus sp. n. from Hyjbopsis amblops (Raf.); D. pronatus sp. n. from Notropis hypselopterus (Gunther); D. venusti sp. n. from Notropis venustus (Girard); D. welakae sp. n. from Notropis welaka Everman and Kendall; Pellucidhaptor eremitus sp. n. from Carpiodes velifer (Raf.); P. orthacis sp. n. from Moxostoma poecilurum (Jordan); P. pterigynus sp. n. from Hypentelium etowanum (Jordan); P. ramulosus sp. n. and P. smithvanizi sp. n. from Minytrema melanops (Raf.). ?f Previously described species found were: Dactylogyrus absidatus Rogers and Mizelle, 1966; D. alabamensis Rogers and Mizelle, 1966; D. anchoratus Wagner, 1857; D. apos Mueller, 1938; D. attenuatus Mizelle and Klucka, 1953; D. aureus Seamster, 1948; D. banghami Mizelle and Donahue, 1944; D. baueri Gussev, 1955; D. bellicae Rogers and Mizelle, 1966; D. bifurcatus Mizelle, 1937; D. bulbus Mueller, 1938; D. bychowskyi Mizelle, 1937; D. confusus Mueller, 1938; D. cornutus Mueller, 1938; D. duquesnei Mueller, 1938; D. extensus Mueller and Van Cleave, 1932; D. formosus Kulwiec, 1927; D. hamatus Rogers and Mizelle, 1966; D. lineatus Mizelle and Klucka, 1953; D. microphallus Mueller, 1938; D. minutus Kulwiec, 1927; D. moorei Monaco and Mizelle, 1955; D. niger Rogers and Mizelle, 1966; D. nuchalis Wood and Mizelle, 1957; D. parvicirrus Seamster, 1948; D. plumbeus Rogers and Mizelle, 1966; D. semotilus Wood and Mizelle, 1957; D. vastator Nybelin, 1924; Pellucidhaptor alabamensis Rogers and Mizelle, 1966. ?[ Aplodiscus gen. n. appears most closely related to Dactylogyrus, but may be distinguished by the absence of a haptoral bar supporting the anchors, absence of anchor wings (filaments), the deep anchor root being an extension of the anchor shaft, and the 4A hooks being larger than in Dactylogyrus. A proposal is made that subfamily diagnosis be emended to include absence of haptoral bars. If The gut of four of the five new species of Pellucidhaptor was observed to be confluent, and P. orthacis was observed to have straight instead of doubly recurved anchor points. All of the Pellucidhaptor species reported herein were observed to inhabit the body rather than the gills. The generic diagnosis is emended to include these characters. [ The generic diagnosis of Dactylogyrus is emended. A ventral bar was observed in all of the new Dactylogyrus species as were the 4A haptoral hooks. The ventral bar is greatly reduced or absent in many specimens, however, and does not warrant upholding Neodactylogyrus Price, 1938. The genus Dactylogyrus was reviewed by Monaco and Mizelle (1955) and a parasitehost:host-parasite checklist presented in addition to describing nine new species. They listed 50 species of Dactylogyrus from North America but the six species described by Kimpel (1939) did not meet the requirements for publication as set forth by the International Rules of Zoological Nomenclature and were declared nomina nuda by Yamaguti (1963). Received for publication 19 September 1966. * Supported by the Southeastern Cooperative Fish Parasite and Disease Project. 501 Wood and Mizelle (1957) described four new species of Dactylogyrus as follows: D. nuchalis from the silvery minnow, Hybognathus nuchalis Agassiz; D. osculus from the dace, Rhinichythys osculus robustus (Rutter); D. rhinichthius from the dace Rhinichthys altratulus meleagris Agassiz; D. semotilus from the creek chub, Semotilus a. atromaculatus

NEOERGASILUS JAPONICUS (POECILOSTOMATOIDA: ERGASILIDAE), A PARASITIC COPEPOD NEW TO NORTH AMERICA

Adult, gravid female Neoergasilus japonicus Harada, 1930 are described from several species of fish from Lee County, Alabama. Samples of bluegill Lepomis macrochirus Rafinesque (n = 25), largemouth bass Micropterus salmoides Lacépéde (n = 6), redear sunfish Lepomis microlophus Gunther (n = 5), and channel catfish Ictalurus punctatus Rafinesque (n = 1) were collected between November 1993 and May 1995. Prevalence of infection was 100% in all fish collected. The dorsal fin was the site of infection containing the highest number of parasites and the anal fin showed the highest frequency of infection. Morphological comparisons are made between this report and previous descriptions, and disparities among them are indicated. New hosts for N. japonicus include largemouth bass, channel catfish, and redear sunfish. This report is the first North American record for the genus Neoergasilus.

Formaldehyde Residue in Striped Bass Muscle

Abstract Tissue residues of formaldehyde were determined for striped bass Morone saxatilis of three size-groups (total length, mean ± SD): 13.0 ± 0.9 cm, 15.5 ± 2.8 cm, and 33.9 ± 1.9 cm. The experiments conducted were a 144-h exposure to a static solution of 25 mg formalin/L (9.3 mg formaldehyde/L) and a 1-h exposure to a static solution of 250 mg formalin/L (92.5 mg formaldehyde/L). There were no statistical differences between formaldehyde residues in untreated (control) fish and fish exposed to 25 mg formalin/L for 24 h, but exposed fish did have significantly higher formaldehyde residues after 48 and 72 h of this treatment. Formaldehyde levels were back to normal after 96 h. Muscle formaldehyde residues were not significantly different between treated and control fish after treatment with 250 mg formalin/L. Additional formaldehyde was produced in tissues of control fish during decomposition during storage.

Electron Microscopy of Infection by Saprolegnia spp. in Channel Catfish

Abstract Saprolegnia sp. isolated from channel catfish Ictalurus punctatus grew slower than S. parasitica on cornmeal agar (CMA). Oogonia in Saprolegnia sp. appeared frequently, whereas oogonia were rarely seen in S. parasitica on CMA. In experimental exposures of injured channel catfish to fungal spores, infections were apparent after 3–4 d, but were most common after 7–9 d. Multiple lesions were usually seen in naturally infected fish, whereas a single lesion appeared at the injured site of experimentally infected fish. No obvious differences were found between lesions caused by S. parasitica and those caused by Saprolegnia sp. Most of the epidermal cells in fungusinfected lesions were necrotic. In some lesions, the epidermis was completely sloughed and the dermis was exposed. Both Saprolegnia parasitica and Saprolegnia sp. penetrated the dermis, causing damage to fibroblasts and collagen lamellae.

Oxytetracycline Residue in Striped Bass Muscle

Abstract Tissue residues were measured in striped bass Morone saxatilis that had been injected intraperitoneally with 50 mg oxytetracycline (OTC)/kg or had been fed a ration containing 75 mg OTC/kg of fish daily for 10 d. Concentration of OTC in muscle of fish fed medicated feed was below the quantitation limit in 67% of the fish 12 d after treatment and was below the quantitation limit in all fish after 16 d at 23°C. The calculated terminal elimination rate constant (β) was 0.20/d (range, 0.15–0.37/d), and the half-life was 2.7 d (range, 1.9–4.5 d). The concentration of OTC in muscle after intraperitoneal injection was below the quantitation limit after 24 d at 23°C. The β-value was 0.34/d and half-life was 2.0 d in fish injected with OTC intraperitoneally.