GROWTH AND SEX RATIO OF OCTOPUS Paroctopus digueti (PERRIER & ROCHEBRUNE, 1894) IN A WILD POPULATION

Istraživanja hobotnice Paroctopus digueti u Meksiku su rijetka te je stoga cilj ovog istraživanja procijeniti neke od bioloških karakteristika navedene vrste u zaljevu Ohuira, Ahome, Sinaloa, u Meksiku. Tijekom jeseni 2016. do jeseni 2017. g. uzorkovano je 217 hobotnica P. digueti od kojih su 166 bile ženke, 31 ovigerne ženke i 20 mužjaka. Svakoj hobotnici je zabilježena dužina plašta (ML) i krakova (AL), ukupna dužina (TL) i ukupna masa (TW), a korišten je FiSAT II program za dobivanje parametara rasta posredstvom frekvencija sezonskih veličina. S obzirom na oba spola, prosječna dužina plašta bila je 40,31 ± 2,5 mm. Za analizu odnosa ML-TL i ML-AL, podaci su prilagođeni modelu linearnog tipa. Za odnos između ML-TL, najmanji je koeficijent determinacije zabilježen tijekom proljeća R2 = 0,34, a najviši je zabilježen zimi R2 = 0,65. Što se tiče koeficijenta alometrije (b), bio je različit u četiri klimatske sezone. Teorijska krivulja rasta ML pokazala je oba spola ML∞ = 73,50 mm, K = 1,30 godina-1 i t0 = 0,10. Procijenjene vrijednosti iz jednadžbe rasta pokazale su brži rast (ML∞ = 63 mm) unutar 1,2 godine njihova života, dostižući maksimalnu duljinu u dobi od 2,5 godine. Krivulja rasta ukupne mase hobotnice P. digueti formirana je eksponencijalnim rastom u prvom stadiju do šest mjeseci, te u drugom, logaritamskom stadiju od sedam mjeseci do približno 1,8 godina. Ljeti su zabilježeni nešto niži koeficijenti i postoci trenutačnog koeficijenata rasta (IGC) za duljine i ukupnu masu hobotnice. Najviši Fultonov indeks kondicije (K) zabilježen je zimi. Omjer spola bio je značajno na strani ženki 9,85 F: 1 M.In Mexico, studies of octopus Paroctopus digueti are scarce, thus the objective of this research is to evaluate some of its biological aspects in Ohuira Bay, Ahome, Sinaloa, Mexico. From autumn 2016 to autumn 2017, a total of 217 organisms of P. digueti were collected, from which 166 were females, 31 ovigerous females and 20 males. The lengths of the mantle (ML), tentacles or arms (AL) and total length (TL) were recorded as well as the total weight (TW) of each organism. The software FiSAT II was used to obtain the growth parameters by mediating seasonal size frequencies. Considering both sexes, the average registered mantle length was 40.31±2.5 mm. For the analysis of ML-TL y ML-AL, the data were adjusted to a linear-type model. For the relationship between ML-TL, the minimum determination coefficient was observed during spring R2 = 0.335, and the highest was registered in winter R2 = 0.6452. With regards to the allometry coefficient (b), it was different among the 4 climatic seasons. The theoretical ML growth curve showed both sexes of ML∞= 73.50 mm, K = 1.30 year-1 and t0= 0.10. The estimated values from the growth equation revealed faster growth (ML∞= 63 mm) within the 1.2 years of their lives, reaching a maximum length at 2.5 years of age. The total weight growth curve of P. digueti octopus was formed by an exponential first stage up to six months and the second logarithmic stage from seven months to approximately 1.8 years. In the summer there were slightly lower coefficients and percentages of instantaneous growth coefficients (IGC) for the lengths and total weight of octopus P. digueti. The highest Fulton’s condition index (k) was recorded in winter. The sex ratio was significant in a proportion of 9.85 F:1 M

Effect of inulin and probiotic bacteria on growth, survival, immune response, and prevalence of white spot syndrome virus (WSSV) in Litopenaeus vannamei cultured under laboratory conditions

The effect of inulin and probiotic bacteria on the growth, survival, immune response and viral prevalence of white spot syndrome virus (WSSV) in white shrimp was evaluated. Presumptive bacilli and lactic acid bacteria (LAB) were characterized for hemolytic and enzymatic activity, hydrophobicity and antagonism against Vibrio. Selected isolates (Bacilli and LAB) were included in the diet of juvenile shrimp. Two bioassays were conducted with treatments by triplicate (10 shrimp per replicate) with inulin and inulin and bacteria. Fourteen LAB and six bacilli isolates had potential as probiotics. Survival and growth was not affected by the addition of the inulin and bacteria to diet. Inulin and bacteria improved immunity in cultured shrimp. Also, these feed additives reduced the prevalence of WSSV in cultured shrimp.Keywords: Probiotics, prebiotics, white spot syndrome virus (WSSV), immune system, Litopenaeus vannameiAfrican Journal of Biotechnology Vol. 12(21), pp. 3366-337

Biodiversity of Gastropod in the Southeastern Gulf of California, Mexico

Currently, studying the environment is important because of the phenomena that take place on the earth every day. That is why it is a priority to carry out studies that relate environmental changes to the biology of organisms. This allows us to know the interactions with the environment, and in this way solve, reduce or prevent ecological and economic problems, if they are organisms with a commercial value. The objective of this investigation is to determine ecological parameters of the gastropod community from the intertidal zone on five islands from the Gulf of California, México, to model the diversity, distribution and abundance of malacological fauna. We considered to evaluate the Shannon-Wiener diversity (H′), Pielou’s of evenness (J) and the Margalef species richness indexes, in order to evaluate through an analysis from biotic and abiotic factors, the species status that was collected from the exposed and non-exposed zone tidal. The generated data were contemplated from a year-based biodiversity project (2016–2017) on the following islands: Patos, Bledos, Bleditos, Tunosa, and Mazocahui which belong to the Ohuira lagoon in Ahome, Sinaloa, southeast of the Gulf of California, México. Likewise a status about the importance of gastropods is mentioned for the study area

Growth and Sex Ratio of Octopus Paroctopus Digueti (Perrier & Rochebrune, 1894) in a Wild Population

In Mexico, studies of octopus Paroctopus digueti are scarce, thus the objective of this research is to evaluate some of its biological aspects in Ohuira Bay, Ahome, Sinaloa, Mexico. From autumn 2016 to autumn 2017, a total of 217 organisms of P. digueti were collected, from which 166 were females, 31 ovigerous females and 20 males. The lengths of the mantle (ML), tentacles or arms (AL) and total length (TL) were recorded as well as the total weight (TW) of each organism. The software FiSAT II was used to obtain the growth parameters by mediating seasonal size frequencies. Considering both sexes, the average registered mantle length was 40.31±2.5 mm. For the analysis of ML-TL y ML-AL, the data were adjusted to a linear-type model. For the relationship between ML-TL, the minimum determination coefficient was observed during spring R2 = 0.335, and the highest was registered in winter R2 = 0.6452. With regards to the allometry coefficient (b), it was different among the 4 climatic seasons. The theoretical ML growth curve showed both sexes of ML∞= 73.50 mm, K = 1.30 year−1 and t0= 0.10. The estimated values from the growth equation revealed faster growth (ML∞= 63 mm) within the 1.2 years of their lives, reaching a maximum length at 2.5 years of age. The total weight growth curve of P. digueti octopus was formed by an exponential first stage up to six months and the second logarithmic stage from seven months to approximately 1.8 years. In the summer there were slightly lower coefficients and percentages of instantaneous growth coefficients (IGC) for the lengths and total weight of octopus P. digueti. The highest Fulton’s condition index (k) was recorded in winter. The sex ratio was significant in a proportion of 9.85 F:1 M

Isolation and characterization of infectious Vibrio sinaloensis strains from the Pacific shrimp Litopenaeus vannamei (Decapoda: Penaeidae)

10 páginas, 2 figuras, 2 tablas[EN] Infectious diseases especially those caused by bacterial and viral pathogens are serious loss factors in shrimp farming. In this study, bacteria were isolated from the gut and hepatopancreas of stressed shrimps obtained from a commercial farm. The isolates were screened on Thiosulfate citrate bile salt sucrose (TCBS) agar plates for the selection of Vibrio species. Presumptive vibrios were characterized through tests for hemolytic and enzymatic activity, hydrophobicity, growth and molecular identification. Three experimental infections were conducted in order to confirm the pathogenicity of selected bacterial strains VHPC18, VHPC23, VHPC24 and VIC30. In the third experimental challenge the LD50 was obtained, it lasted 10 days with 10 shrimp, weighing 6.9±1.1g, per tank. The treatments in triplicate were: (1) saline solution (control group); (2) 2×105CFU/shrimp; (3) 4×105CFU/shrimp; (4) 2×106CFU/shrimp; (5) 4×106CFU/shrimp, and (6) 8×106CFU/shrimp. In all challenges, water parameters measured during the experimental period remained within optimum ranges. Pathogenicity tests confirmed that the mixture of four vibrio isolates, identified as Vibrio sinaloensis, was virulent for L. vannamei. The LD50 value was 1.178×105CFU/g body weight. V. sinaloensis may act as opportunistic pathogens for cultured L. vannamei.[ES] Las enfermedades de etiología infecciosa, especialmente las causadas por patógenos bacterianos y virales ocasionan graves pérdidas en el cultivo de camarón blanco Litopenaeus vannamei. En este estudio se caracterizó: la actividad enzimática y hemolítica; hidrofobicidad; crecimiento e identificación molecular de vibrios aislados del intestino y hepatopancreas de camarones estresados, obtenidos de una granja comercial, en medio Agar Tiosulfato Citrato Bilis Sacarosa. Además, se realizaron tres infecciones experimentales para confirmar la patogenicidad de las cepas bacterianas seleccionadas VHPC18, VHPC23, VHPC24 y VIC30. En la tercera infección experimental se obtuvo la LD50, el reto duró 10 días, con 10 camarones por tanque con un peso de 6.9±1.1g. Los tratamientos se realizaron por triplicado: (1) solución salina (grupo control); (2) 2×105UFC/camarón; (3) 4×105UFC/camarón; (4) 2×106UFC/camarón; (5) 4×106UFC/camarón y (6) 8×106UFC/camarón. En todos los retos, los parámetros del agua permanecieron dentro de los intervalos óptimos. Las pruebas de patogenicidad confirmaron que la mezcla de cuatro aislados de Vibrio, identificados como Vibrio sinaloensis, fue virulenta para L. vannamei. El valor de la LD50 fue de 1.178×105UFC/g de peso corporal. Los resultados permiten establecer que las cepas de V. sinaloensis pueden actuar como patógenos oportunistas en L. vannamei cultivado.Authors are grateful to Consejo Estatal de Ciencia y Tecnología del Estado de Sinaloa (CECyT-Sinaloa) and to the Secretaría de Investigación y Posgrado del Instituto Politécnico Nacional (SIP-IPN) for financial support. Ma. del Carmen Flores Miranda acknowledges CONACYT-Mexico and SIP-IPN for the M.Sc. grantsPeer reviewe

Screening for potential probiotic bacteria to reduce prevalence of WSSV and IHHNV in whiteleg shrimp (Litopenaeus vannamei) under experimental conditions

Abstract This study evaluated the effect of Pediococcus pentosaceus and Staphylococcus hemolyticus as probiotics in whiteleg shrimp Litopenaeus vannamei naturally infected with WSSV and IHHNV. All bacteria were isolated from the gut of wild brown shrimp (Farfantepenaeus californiensis). Presumptive lactic acid bacteria were characterized for hemolytic and enzymatic activity, hydrophobicity, growth, and molecular identification. Two mixtures of four isolates were tested and their effect measured on the hemocyte number, survival, and prevalence of WSSV and IHHNV. Each mixture was applied at two different concentrations in a 15-day bioassay with shrimp naturally infected with WSSV and IHHNV as determined by single and/or nested PCR. In the treated animals total hemocyte count and survival were similar to control group. All shrimp fed with bacterial mixtures showed a decrease in the prevalence of WSSV but not IHHNV. The results obtained in this preliminary study revealed a protective effect of the two bacterial mixtures against WSSV latent infections

Effect of inulin and probiotic bacteria on growth, survival, immune response, and prevalence of white spot syndrome virus (WSSV) in Litopenaeus vannamei cultured under laboratory conditions

The effect of inulin and probiotic bacteria on the growth, survival, immune response and viral prevalence of white spot syndrome virus (WSSV) in white shrimp was evaluated. Presumptive bacilli and lactic acid bacteria (LAB) were characterized for hemolytic and enzymatic activity, hydrophobicity and antagonism against Vibrio. Selected isolates (Bacilli and LAB) were included in the diet of juvenile shrimp. Two bioassays were conducted with treatments by triplicate (10 shrimp per replicate) with inulin and inulin and bacteria. Fourteen LAB and six bacilli isolates had potential as probiotics. Survival and growth was not affected by the addition of the inulin and bacteria to diet. Inulin and bacteria improved immunity in cultured shrimp. Also, these feed additives reduced the prevalence of WSSV in cultured shrimp

Screening for potential probiotic bacteria to reduce prevalence of WSSV and IHHNV in whiteleg shrimp (Litopenaeus vannamei) under experimental conditions

This study evaluated the effect of Pediococcus pentosaceus and Staphylococcus hemolyticus as probiotics in whiteleg shrimp Litopenaeus vannamei naturally infected with WSSV and IHHNV. All bacteria were isolated from the gut of wild brown shrimp (Farfantepenaeus californiensis). Presumptive lactic acid bacteria were characterized for hemolytic and enzymatic activity, hydrophobicity, growth, and molecular identification. Two mixtures of four isolates were tested and their effect measured on the hemocyte number, survival, and prevalence of WSSV and IHHNV. Each mixture was applied at two different concentrations in a 15-day bioassay with shrimp naturally infected with WSSV and IHHNV as determined by single and/or nested PCR. In the treated animals total hemocyte count and survival were similar to control group. All shrimp fed with bacterial mixtures showed a decrease in the prevalence of WSSV but not IHHNV. The results obtained in this preliminary study revealed a protective effect of the two bacterial mixtures against WSSV latent infections

Dietary microorganism and plant effects on the survival and immune response of Litopenaeus vannamei challenged with the white spot syndrome virus.

The effect of plants and probiotics on the survival and immune response of Litopenaeus vannamei challenged with the white spot syndrome virus (WSSV) was evaluated. A probiotic mixture (PM), plant extract (PE) or powdered plants (PP) were added to feed with the attractant Dry Oil. An experiment was conducted with ¢ve treatments in triplicate. Shrimp were cultured in120 L plastic tanks and fed twice a day with commercial feed plus additives orwith commercial feed plusWSSV. Animals weremonitored for the occurrence ofWSSVusing single- step and nested PCR. The PMand PP added to the commercial feed showed high survival, a decrease in WSSVprevalence in shrimp and an increase in the activity of lysosomal enzymes, N-acetyl-b-glucosaminidase and acid phosphatase. The total haemocyte count in shrimp treated with PM was signi¢cantly higher than that in the control group (treatment I) and in shrimp fed with PE. The results of the present work indicate that PP and PMare good candidates for use as feed additives againstWSSVin shrimp cultures

Respuesta inmune y expresión de genes en el camarón blanco (Litopenaeus vannamei) inducida por inmunoestimulantes microbianos

Se realizó un bioensayo de 26 días para evaluar el efecto inmunoestimulante de bacterias ácido lácticas y levaduras (MI), adicionadas en el alimento, en Litopenaeus vannamei. Los tratamientos del bioensayo se realizaron por triplicado: I) dieta control (Camaronina®); II) MI en alimento, diario; III) MI en alimento, cada tres días y; IV) MI en alimento, cada seis días. Los camarones sólo eran libres de WSSV. Para el estudio del sistema inmune se hizo un conteo total de hemocitos, se determinó bioquímicamente la concentración de anión superóxido, y la actividad de la fenoloxidasa. También se estudió la expresión semicuantitativa de seis genes del sistema inmune, utilizando la técnica de RT-PCR. No hubo aumento significativo en el crecimiento y la supervivencia, el conteo total de hemocitos, la concentración de la proteína total en plasma y hemocitos, y la concentración del anión superóxido. La actividad de la fenoloxidasa en plasma en el tratamiento IV fue significativamente mayor que en los tratamientos I, II y III. La fenoloxidasa del SLH (proFO) en el tratamiento IV fue significativamente mayor que en los tratamientos I y III. La MI provocó una sobreexpresión significativa de los genes que codifican para la profenoloxidasa (tratamiento IV), lisozima (tratamiento III) y transglutaminasa (tratamiento II), con respecto a los animales no tratados (control). La mezcla de inmunoestimulantes microbianos puede aumentar la resistencia de L. vannamei contra patógenos en los cultivos