Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Bacterial load comparison of marine fish collected and commercially obtained for human consumption in western region of Yucatan Peninsula, Mexico 6 12 EN Romero Jarero Jorge Pilar Negrete Redondo María del Carmen Monroy Dosta <span>This study determined the presence of human pathogenic bacteria in fish muscle, recollected at moment of their capture and during their process for sale in marketing sites. The samples were recollected in eighth touristic and fishing zones of Mexican Caribbean. </span><span>Samples were inoculated by duplicates in agar plates of specific environment of: S-S, EMB and TCBS and were incubated at 36ºC during 24 hrs.. </span><span>Strains were identified according to Merck (1994) criteria and finally, in order to confirm the identification with the commercial kit API-20E. Species of different bacterial families were identified, such as: Enterobacteriaceae; <em>Salmonella hirschfeldii, Salmonella schottmulleri, Salmonella parathipi, Salmonella typhi, Salmonella enteritidis, Proteus miriabilis, Proteus rettgeri, Proteus vulgaris, Citrobacter freundii, Citrobacter amanolaticus </em>and three varieties of <em>Escherichia Coli</em>; Pseudomonadaceae: <em>Pseudomonas fluorescens;</em> Aeromonadaceae: <em>Aeromonas hydrophila</em> and Vibrionaceae: <em>Vibrio fluviales, V. cholerae El Tor </em>and <em>V. parahaemolyticus. </em>The 70.6% of the samples presented a bacterial growth; 46% in recently captured fish, and 54% in market fish. It was demonstrated that fish is already contaminated by pathogenic bacteria in their natural environment and that handling during their commercialization does not significantly increase their bacterial load. </span> Pathogenic bacteria,fish muscle,fecal contamination,public health http://www.journal-aquaticscience.com/article_70929.html http://www.journal-aquaticscience.com/article_70929_5a519125007a21593b2e1451d20cc74f.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Egg Development of Backcrossed Hybrid Grouper between OGGG (Epinephelus coioides × Epinephelus lanceolatus) and Giant Grouper (Epinephelus lanceolatus) 13 18 EN Gan Hwa Luan Marianne Luin Rossita Shapawi Ching Fui Fui Shigeharu Senoo <span>The hybrid grouper, OGGG is produced from a cross-breed between a female orange-spotted grouper (OG; <em>Epinephelus coioides</em>) and a male giant grouper (GG; <em>E. lanceolatus</em>). OGGG is an excellent hybrid grouper in Southeast Asia owing to its outstanding organoleptic qualities. GG is the most favorable species in aquaculture industry driven by its notable characteristics. With the purpose of producing a superior aquaculture species, a backcross-breed between OGGGs and GGs was conducted. A sexually matured female OGGG was selected and treated twice with Human Chorionic Gonadotropin (HCG). Subsequently, the stripped eggs were fertilized with preserved sperm of GG and incubated in a circular fiberglass reinforced plastic (FRP) tank. Observation on stripped eggs, egg development and developed time on each egg stage was recorded under microscope. The fertilized eggs were spherical with a mean diameter of 755 ± 28 µm (n = 20). The fertilization rate and hatching rate were 23.3 % and 1.5 %, respectively. The hatching time was commenced from 22:40 to 24:40 hours after hatching (hAF). It was undergone normal egg development and successfully survived up to 11 dAH. It is possible to produce backcrossed OGGG and GG and beneficial to the production of hybrid grouper in aquaculture industry.</span> backcross- breed,hybrid grouper OGGG,giant grouper,egg development http://www.journal-aquaticscience.com/article_70920.html http://www.journal-aquaticscience.com/article_70920_3c0f664d987e26568949bcd3c54215c5.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Effects of Nicotina tobacum (Linnaeus) on the survival and behavioral response of the freshwater leeches, Hirudinaria sp. 19 24 EN Erick Ochieng Ogello Elija Migiro Kembenya Kevin Odhiambo Obiero Jonathan Mbonge Munguti <span>We investigated the efficacy of <em>Nicotina tobacum</em> as an anti-parasitic chemical to freshwater leeches of the genus <em>Hirudinea</em>, by assessing their behavioral and survival responses to different concentrations and ages of <em>N. tobacum</em> (i.e. 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 17.5 and 20.0 g L </span>^{<span>-</span><span>1</span>}<span>) at 25±1^oC. We observed longer escape time from freshly prepared tobacco solutions compared to 1- day 2- day and 3- day-old solutions, suggesting a gradual degradation of nicotine toxicity with time. The percentage survival decreased significantly (<em>P</em><0.05) with increasing concentrations of <em>N. tobacum</em> and exposure time. Concentrations of 15.0, 17.5 and 20.0 g L</span>^{<span>-</span><span>1</span>}<span> recorded highest hazard ratios and low survival rates of leeches. The lethal concentration (LC₅₀) and time (LT₅₀) at which 50 % of leeches died were 15.0 gL^-1 and 73 min respectively. This finding can be applied to control leeches, which are potential human disease vectors in aquatic ecosystems<em>.</em> Further investigations should target effects of nicotine on cultured animals and water quality parameters. </span> Hirudinea sp,Nicotina tobacum,leeches,lethal concentration,lethal time http://www.journal-aquaticscience.com/article_70923.html http://www.journal-aquaticscience.com/article_70923_773f0206bb04edb8fcbddd4d38d342bf.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Effects of salinity and hardness on survival of Poblana letholepis (Atheriniformes: Atherinopsidae) larvae 25 29 EN Tannia Cristina Frausto Illescas María Cecilia Hernández-Rubio Gerardo Figueroa-Lucero <em><span>Poblana letholepis</span></em><span> is an endemic fish from crater-lake La Preciosa, Puebla, at the Mexican Plateau, Mexico. It has been a great resource for local people since pre-Hispanic times. This species is at risk of extinction due to its habitat loss in addition to the lack of knowledge about its biology. Survival and development time of <em>P. letholepis</em> were evaluated from hatching to metamorphosis to juvenile, with 20 free embryoL</span>^{<span>-1</span>}<span> reared at 0, 4, 8, 12 and 16 gL^-1 salinities and 160-180, 80-100 and 40-48 mgL^-1 CaCO₃, 20 ºC, pH 7.6 and 5 mgL^-1 O_2,under a bifactorial design (5 x 3 levels) with three replicates per treatment. Larvae were fed with rotifers (<em>Brachionus plicatilis</em>) and <em>Artemia</em> nauplii. Treatments showed differential effects on survival (ANOVA II, P < 0.05) but not in juvenile metamorphosis time (50 </span><span>±</span><span> 0.25 dph) (ANOVA II, P > 0.05). Salinity presented a significative effect on final survival, only. However, there was an interaction between these factors. The highest survival was observed at 4-8 gL^-1 salinity and 160-180 mgL^-1 CaCO₃ (80-65%) and 80-100 mgL^-1 CaCO₃ (60-70%). Major survival of <em>P. letholepis</em> larvae, is probably due to physiological mechanisms such as increased excretion of sodium by chloride cells proliferation in hard water.</span> Species conservation,Salinity,water hardness,silverside http://www.journal-aquaticscience.com/article_70932.html http://www.journal-aquaticscience.com/article_70932_581f6d4052ce15093cc48256a73b8f74.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Occurrence of pathogenic bacteria in surface water of an urban river in Argentina (Reconquista River, Buenos Aires) 30 38 EN David Kuczynski Buenos Aires city and surroundings is one of the largest 20 urban agglomerations in the World. It is crossed by the Reconquista River, a lowland course directly associated with millions of people. The present study deals with an assessment of microbial populations from surface wateralong the main course and its tributaries <em>over a period of three years. These watercourses </em>showed high levels of total bacteria and coliform densities. The following s<em>eventeen bacterial species were identified: </em><em>Acinetobacter baumannii, Aeromonas hydrophila, Burkholderia cepacia, Chromobacterium violaceum, Citrobacter freundii, Cronobacter sakazakii, Erwinia <em>carotovora, </em>Escherichia coli, Photobacterium damselae, Providencia rettgeri, Pseudomonas aeruginosa, P. luteola, P. oryzihabitans, Serratia fonticola, S. marcescens, S. odorifera </em>and <em>Vibrio fluvialis </em><em>These include </em>pathogens related with nosocomial infections. Their implications for human health as well as for the aquatic ecosystems are analyzed. Aquatic bacteria,urban river ecology,river pollution,Reconquista River basin (Argentina) http://www.journal-aquaticscience.com/article_70922.html http://www.journal-aquaticscience.com/article_70922_24dad312a5d881f782f12e5567a39b51.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Seasonal Dynamics of Physico-chemical Characteristics in Wetlands of Northern Region (Ghana): Implications on the Functional Status 39 49 EN Collins Ayine Nsor Emmanuel Acquah Clifford A. Braimah <span>Seasonal variations of 11 water quality, namely; pH, TDS, Conductivity, Turbidity, surface water temperature, DO, NH₃, PO₄, NO₃-N, Ca²⁺ and Mg²⁺, were assessed in six wetlands, in the dry (December - April) and wet (July–October) seasons for two years, using standard APHA Four major environmental disturbances (farming activities, bushfires, grazing activity, illegal fishing methods) were quantified using <em>Battisti </em>and <em>Salafsky models</em>. Although physical parameters values showed an increase in the dry season compared to the wet season, they were not statistically significant (p<em>></em>0.05). However, hydro-chemical parameters showed significant seasonal variations (p< 0.05). With the exception of NH₃ that was in far excess of the required levels acceptable for aquatic life, in Nabogo and Bunglung sites, the remaining hydro-chemical variables were at tolerable levels necessary for aquatic life. Elevated levels of NH₃ and turbidity in these sites were linked to surface run-off from nearby agricultural fields, while turbidity levels showed appreciable levels in Kukobila (395±2.7 NTU) in the wet seasons, compared with the remaining sites. DO levels were lower beyond acceptable limit and partly influenced by surface water temperature. Our results revealed that farming practices and bushfires directly influenced water quality. Consequently, wetlands functional status could degrade further in the near future if current disturbances intensify. Thus managers of wetlands could institute conservation measures, in order to curb future disturbances and enhance.</span> Water Quality,environmental disturbance,seasonality,Cluster analysis http://www.journal-aquaticscience.com/article_70935.html http://www.journal-aquaticscience.com/article_70935_4922a05af9168ed8e973a71a84dd4ef3.pdf

Int. J. of Aquatic Science 2008-8019 7 1 2016 01 01 Chirostoma estor (Jordan, 1879) a species in vulnerability, with alternatives for its preservation 50 55 EN Diego Alberto O. Retana Javier S. Velasco Ma. De los Angeles M. Peralta http://www.journal-aquaticscience.com/article_70924.html http://www.journal-aquaticscience.com/article_70924_5bf76cdb503bd47f29848cfc350485e6.pdf