Heliconema savala n.sp. (Nematoda:Physalopteridae) from marine fish Lepturacanthus savala (Cuvier) (Trichiuridae) and Psettodes erumei (Schneider) new host (Pisces:Pettodidae) of Physalopterid Nematode, Bulbocephalus inglisi Rasheed, 1966 in Pakistan

Helicnonema savala, n.sp. obtained from the marine fish, Lepturacanthus savala in Sindh coast is distinguished from members of the genus processing in the male 10 tessellated longtitudinal ridges and a spicule ratio 1:15. Females have vulvular flap. Heliconema savala is a morphologically most closely related to Heliconema heliconema. The marine fish, Psettodes erumei is recorded as a new host of Bulbocephalus inglisi.

Helminth parasites of Caspian kilka (genus Clupeonella) as bioindicators of heavy metals

In the present study, intestinal helminth parasite fauna of 398 specimens of three species of kilkas, C. engrauliformis (N= 92), C. grimmi (N= 136) and C. cultriventris (N= 170) from Babolsar harbor were investigated. Five parasite species were found including: Corynosoma strumosum (Acanthocephala), Pronoprymna ventricosa (Trematoda), Contracaecum sp. (Nematoda), Raphidascaris sp. (Nematoda) and Anisakis sp. (Nematoda). The highest prevalence and abundance were observed in C. strumosum and P. ventricosa. The prevalence and abundance of C. strumosum in C. grimmi was significantly higher than C. engrauliformis. The prevalence and abundance of P. ventricosa in C. cultriventris was significantly higher than C. engrauliformis. The prevalence, mean intensity and mean abundance of the parasites were compared according to the sex, length group and season also effect of parasite on host growth parameters was considered. The diversity, equability, similarity, species richness, dominance Indices and specificity indices of helminth parasites of the three host species were studied. Also the lead and cadmium concentrations in the intestine, muscle, liver, kidney and gonad of kilkas and their parasites C. strumosum and P. ventricosa were measured and compared. The results revealed that lead and cadmium concentrations in C. strumosum and P. ventricosa were significantly higher than kidney, liver, intestine, gonad and muscle. The lead and cadmium concentrations of the parasites were compared according to the sex, parasitism and season.

Genetic evidence of two sibling species within the Contracoecum ogmorhini Johnson & Mawson 1941 complex (Nematoda; Anisakidae) from otariid seals in boreal and austral regions

Genetic variation of Contracaecum ogmorhini (sensu lato) populations from different otariid seals of the northern and southern hemisphere was studied on the basis of 18 enzyme loci as well as preliminary sequence analysis of the mitochondrial cyt b gene (260 bp). Samples were collected from Zalophus californianus in the boreal region and from Arctocephalus pusillus pusillus, A. pusillus doriferus and A. australis from the austral region. Marked genetic heterogeneity was found between C. ogmorhini (sensu lato) samples from the boreal and austral region, respectively. Two loci (Mdh-2 and NADHdh) showed fixed differences and a further three loci (Iddh, Mdh-1 and 6Pgdh) were highly differentiated between boreal and austral samples. Their average genetic distance was DNei = 0.36 at isozyme level. At mitochondrial DNA level, an average proportion of nucleotide substitution of 3.7% was observed. These findings support the existence of two distinct sibling species, for which the names C. ogmorhini (sensu stricto) and C. margolisi n. sp., respectively, for the austral and boreal taxon, are proposed. A description for C. margolisi n. sp. is provided. No diagnostic morphological characters have so far been detected; on the other hand, two enzyme loci, Mdh-2 and NADHdh, fully diagnostic between the two species, can be used for the routine identification of males, females and larval stages. Mirounga leonina was found to host C. ogmorhini (s.s.) inmixed infections with C. osculatum (s.l.) (of which C. ogmorhini (s.l.) was in the past considered to be a synonym) and C. miroungae; no hybrid genotypes were found,confirming the reproductive isolation of these three anisakid species. The hosts and geographical range so far recorded for C. margolisi n. sp. and C. ogmorhini (s.s.) are given.

Nuevos ensayos para obtener la reproducción artifical de las percas o truchas criollas (Percichthys sp.).

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An integrated assessment of the continued spread and potential impacts of the colonial ascidian, Didemnum sp. A, in U.S. waters

Didemnum sp. A is a colonial ascidian or “sea squirt” of unknown geographic origin. Colonies of Didemnum sp. A were first documented in U.S. waters in 1993 at Damariscotta River, Maine and San Francisco Bay, California. An alarming number of colonies have since been found at several locations in New England and along the West Coast of the contiguous continental United States. Originally believed to be restricted to artificial structures in nearshore habitats, such as ports and marinas, colonies of Didemnum sp. A have also been discovered on a gravel-pavement habitat on Georges Bank at depths of 40-65m. The wide distribution of Didemnum sp. A, the presence of colonies on an important offshore fishing ground, and the negative economic impacts that other species of noninidigenous ascidians have had on aquaculture operations have raised concerns about the potential impacts of Didemnum sp. A. We reviewed the available information on the biology and ecology of Didemnum sp. A and potentially closely related species to examine the environmental and socioeconomic factors that may have influenced the introduction, establishment and spread of Didemnum sp. A in U.S. waters, the potential impacts of this colonial ascidian on other organisms, aquaculture, and marine fisheries, and the possibility that it will spread to other U.S. waters. In addition, we present and discuss potential management objectives for minimizing the impacts and spread of Didemnum sp. A. Concern over the potential for Didemnum sp. A to become invasive stems from ecological traits that it shares with other invasive species, including the ability to overgrow benthic organisms, high reproductive and population growth rates, ability to spread by colony fragmentation, tolerance to a wide range of environmental conditions, apparent scarcity of predators, and the ability to survive in human dominated habitats. At relatively small spatial scales, species of Didemnum and other nonindigenous ascidians have been shown to alter the abundance and composition of benthic assemblages. In addition, the Canadian aquaculture industry has reported that heavy infestations of nonindigenous ascidians result in increased handling and processing costs. Offshore fisheries may also suffer where high densities of Didemnum sp. A may alter the access of commercially important fish species to critical spawning grounds, prey items, and refugia. Because colonial ascidian larvae remain viable for only 12–24hrs, the introduction and spread of Didemnum sp. A across large distances is thought to be predominantly human mediated; hull fouling, aquaculture, and ballast water. Recent studies suggest that colony growth rates decline when temperatures exceed 21 ºC for 7 consecutive days. Similarly, water temperatures above 8 to 10 ºC are necessary for colony growth; however, colonies can survive extended periods of time below this temperature threshold as an unidentified overwintering form. A qualitative analysis of monthly mean nearshore water temperatures suggest that new colonies of Didemnum will continue to be found in the Northeast U.S., California Current, and Gulf of Alaska LMEs. In contrast, water temperatures become less favorable for colony establishment in subarctic, subtropical, and tropical areas to the north and south of Didemnum’s current distribution in cool temperate habitats. We recommend that the Aquatic Nuisance Species Task Force serve as the central management authority to coordinate State and Federal management activities. Five objectives for a Didemnum sp. A management and control program focusing on preventing the spread of Didemnum sp. A to new areas and limiting the impacts of existing populations are discussed. Given the difficulty of eradicating large populations of Didemnum sp. A, developing strategies for limiting the access of Didemnum sp. A to transport vectors and locating newly established colonies are emphasized. (PDF contains 70 pages)

Prevalence, intensity, longevity, and persistence of Anisakis sp. larvae and Lacistorhynchus tenuis metacestodes in San Francisco striped bass

Thirteen hundred and seventy-three striped bass, Marone saxatilis, were collected from the San Francisco Bay-Delta area to correlate host diet with parasitic infections and to determine the prevalence, intensity, longevity, and persistence of larval Anisakis sp. nematodes and the metacestode Lacistorhynchus tenuis. There is an increase in the prevalence and intensity of Anisakis sp. and in the intensity of L. tenuis with increase of age of the host. These increases are probably related to the diet and the persistence of tbe parasites. The infections of both species are overdispersed. San Francisco Bay striped bass are an incompatible host for both species of parasites. Degenerated Anisakis sp. will remain in lhe host for at least 8 months and L. tenuis metacestodes for 22 months. The occurrence of several other species of parasites and a tumor are also reported. (PDF file contains 10 pages.)

Incidence of mayfly (Povilla sp.) infestation of wooden infrastructures of artisanal fishers in the lagoon and marine fisheries locations of Ogun State, Nigeria

A diagnostic survey of the incidence of mayfly (Povilla sp.) infestation of wooden infrastructures of the artisanal fishers in ten (10) lagoons and marine fishing villages of Ogun States (Nigeria) was carried out through the application of structured questionnaire and participatory Rural Appraisal interviews. The demographic, infrastructural and socioeconomic characteristics of the ten fishing villages sampled were derived and analyzed. The infestation which occurs all year round is found to be most prevalent (70%) in the wet season, increasing proportionally with salinity from 56% (brackish water); to 63% (marine water). The life-span of Povilla sp. is reduced from 55% to 62% (freshwater); 41% (brackish water) and 38% (marine water). Annual financial loss of N10,000.00 per fisher or N80,000,000.00 to the 8000 artisanal fishers affected in Ogun State is discussed. It is recommended that fishers should preferably use non-wood crafts and infrastructures while adopting appropriate management strategies for containing the existing infestation

Neues vom Heringsparasiten Ichthyophonus sp.

Seit dem Massensterben von Heringen entlang der schwedischen Südküste im Sommer 1991, aufgrund einer Infektion mit dem parasitischen Pilz Ichthyophonus sp., wird der Gesundheitszustand der Heringsbestände in den europäischen Seegebieten intensiv überwacht. Diese Untersuchungen, an denen sich auch die Bundesforschungsanstalt für Fischerei beteiligt, werden koordiniert von der "Arbeitsgruppe über Pathologie und Krankheiten mariner Organismen" des Internationalen Rates für Meeresforschung (ICES). Im folgenden sollen als Ergänzung eines in den Inf Fischw. 39(2) erschienenen Artikels (Lang 1992) neuere Erkenntnisse und Hypothesen zur Verbreitung der Epidemie und zu ihren möglichen Ursachen diskutiert werden.

Different patterns of uptake and depuration of cadmium by periphyton community and a grazer species (Physa sp.): A mesocosm evalution

Widespread pollution by heavy metals generated by various industries has serious adverse effects on human health and the environment. Cadmium is a heavy metal recognised as one of the most hazardous environmental pollutants. It is a non-essential and non-beneficial element to organisms, causing toxicity and other deleterious effects on various components of the aquatic environment. The ability of algal periphyton to concentrate cadmium from fresh water is well known. Moreover, periphyton communities are able to accumulate large amounts of cadmium despite its low concentration in fresh water. Many researchers use algal periphyton as an indicator of water quality in aquatic environments. In the present study, the authors ask two basic questions: Does cadmium accumulate along a food chain consisting of the periphyton community and a grazer species (Physa sp.) under semi-natural conditions provided by artificial streams? If not, which one can better indicate the water quality?

Selective plankton feeding by the coregonid ”bondella” (Coregonus sp.) of Lake Maggiore [Translation from: Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 31 181-203, 1974]

In recent times, some specialists have begun to study the subject of food selection of fish in an organized way, thus highlighting its importance. In the present work, the author intends to evaluate the impact of predation on the eupelagic zooplanktonic biocenosis of Lake Maggiore, producing, in this way, as far as possible, a basis for a better understanding of the population dynamics of the species of zooplankton directly involved. Another aspect which has been studied is that related to the mechanism of selective capture set in action by the predator. To this end the study tries to bear in mind that the subject should be interpreted as a function of numerous factors acting contemporaneously, that is as the interaction of characters peculiar to the predator and to the prey. The species studied, locally called ”bondella”, belongs to the family Salmonidae, subfamily Coregoninae and was introduced into Lake Maggiore in 1950.

Dangeardia sporapiculata n.sp., the term 'apiculus' and the species limitation of some chytrids [Translation from: Sydowia 16 324-330, 1963]

Taxonomic observations are given on Dangeardia sporapiculata n. sp. Furthermore the term 'apiculus' and the species limitation of some chytrids are being discussed. It is concluded that the newly described species Dangeardia sporapiculata does not fit satisfactorily into the present system of phlyctidiacee, because their characteristics do not agree exactly with any genus.

Copépodos calanoideos marinos del área de Mar del Plata con la descripción de Pontella marplatensis n.sp

This paper deals with the Calanoidean Copepod of the Mar del Plata area (Province of Buenos Aires, Argentina) which were obtained in 71 starions during 5 oceanographic cruises performed on April, August-September and December, 1963 and on March and May, 1964. The area under study ranges from 37°20' to 38°45' L.S. and from 56°30' to 58°10' L.W. The samples were gathered from coastal, surface waters. Quantitative data could not be obtaine, except for and estimation of the time of flow through the plakton net. A total of 13 species of Calanoid Copepods were found. The species found were described, and drawings were made of those structures wich ere considered of taxonomic value. Data were included on the geographic distribution, with emphasis on South Atlantic and areas Antarctic.