Variacion Estacional Octopus Maya

Seasonal characterization of the physiological condition of

Octopus maya

UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO, Programa Pulpo, Sisal, Yucatán, México •Pascual Cristina, Mascaró Maite, Sánchez Ariadna, Cruz Honorio and Rosas Carlos [email protected]

Supporting an important fishery, Octopus maya is an endemic species of México with a short life cycle and reproductive period from December to July. There is little information on the physiology of wild octopus; hence, our objective was to determine the seasonal variation in physiological conditions of adults off the coast of Sisal, Yucatán. Dry

Table 1. Seasonal variation of some physiological indicators.

Three days of sampling at each season

* Sampling day was included as a random explanatory factor ** p < 0.01, *** p < 0.001 for Liklihood ratio.

Individual tanks Norths

Rainy

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Fig. 1 and 2 Relative weight and lipids of the digestive gland as functions of body weight. Filled dots are observed values for females, while open dots are those for males. Lines represent fitted mean values for each sex, respectively.

Anesteshia

Fifty individuals in each of three climatic seasons were captured, acclimated for one day, and anesthetized with low temperature to obtain tissues.

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Fig. 3 and 4 Glycogen of the muscle and lipids of the gonads as functions of body weight. Filled dots are observed values for females, while open dots are those for males. Lines represent fitted mean values for each sex, respectively.

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Hemolymph extraction from the aorta

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Protocol used to obtain hemolymph and anesthesia were established first for

Octopus maya.

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Hemolymph was used to evaluate the osmotic capacity, hemocytes concentration, hemocyanin, total protein, glucose, cholesterol and acylglicerols. Gonads, digestive gland and muscle were used to determine the glycogen concentration and total lipids. The caloric value of muscle was also determined. A two-way ANOVA (season or body weight and sex) was applied to all response variables, sampling days were nested in each season as a random explanation factor. Procedures in generalized linear mixed modeling were used to ensure compliance with regression assumptions.

Fig. 5 Plasmatic glucose as a function of body weight. Filled dots are observed values. Lines represent fitted mean values for both sexes, altogether.

Season variation was observed in body weight, hemocyanine, hemocytes and osmotic capacity. Plasmatic glucose and cholesterol, lipids of digestive gland, lipids in the gonad, glycogen of muscle and gonad-somatic index showed a significant correlation with weight. Additional differences were found amongst males and females in the 4 latter variables. The pattern observed indicates a seasonal

variation associated with peaks in breeding and growth of organisms. These results provide reference values for sub-adult and adult Octopus maya, whilst several of evaluations are reported for first time for this species.

ACKNOWLEDGMENTS The authors thank Richard Mena , Luis Jiménez and Claudia Caamal for their invaluable technical support. This study was funded by the projects: PAPIIT-UNAM IN-213008 and CONACyT Reference numbers 00090574.