Octopus maya Research Papers - Academia.edu (original) (raw)

The main objective of this research was to provide reproductive knowledge of Octopus maya Voss y Solís-Ramírez, 1966, through its life history, as support for the recent Octopus Fisheries Management Plan and its respective action line No.... more

The chapters of this dissertation consist of individual manuscripts, prepared to submit/send to journals in areas like malacology and/or marine science and/or biology of reproduction, except Chapter 1 (general introduction) and Chapter 6 (general conclusion). Although each chapter is intended to be independent and can be understood without reference to the other, there is an overlap of the subject and all chapters are devoted to reproductive and biological aspects consecutive along the life history of O. maya.

Chapter 1 presents a general introduction on reproductive aspects of octopuses (e.g., structures, maturity, hormonal control), the antecedents about reproductive biology to O. maya, the measurements of fisheries management, and the recently created Plan for Management of Octopus Fisheries with its components and action lines. The objectives of this doctoral research are also reflected.

Chapter 2 describes the development of the gonad during early life of O. maya in terms of histology and morphology, using maintenance octopus (culture), since hatching and through the juvenile stage. In this chapter sets the stage for (a) understand the stages from early life history of O. maya, (b) to recognize the length-weight relationship in an attempt to separate the sexes at the beginning of the life history (for maintenance of culture), (c) to determine whether sexual maturation is a process that starts early in this, and (d) to distinguish sequences of growth or "life history stages", based on consistent terminology: juvenile, sub-adult, and adult.

In the Chapter 3 adapts, develops and validates a solid phase radioimmunoassay, using two components commercially available: 125I-labeled hormones and specific antibody. Also, a hormone extraction protocol was described in order to measure the concentrations of progesterone and testosterone in extracts of gonads octopus O. maya. The third chapter provides the tools and methodology for assessing the reproductive endocrine context of organisms moving a stock (recruitment) reproductive (i.e., adults).

Chapter 4 describes some reproductive aspects of O. maya from Sisal, Yucatan, Mexico, such as: (1) sex ratio, (2) the reproductive cycle based on histology and through five reproductive indices and by frequency of gonad developmental stages, (3) the frequency of non- vitellogenic and vitellogenic oocytes, (4) and the mean size of sexual maturity. The possible effect of weather (seasons) on the reproductive aspects of this species in the study area is also analyzed. This chapter provides the basic knowledge of reproductive biology that can help improve the current fishing regulation measures such as closures season (with the reproductive cycle) and minimum landing sizes (the mean size of sexual maturity).

In Chapter 5, the seasonal changes of progesterone and testosterone in the gonads of females and males through annual period are quantified. The relationship between the concentrations of steroid hormones (progesterone and testosterone) to events of the reproductive cycle represented by maturity indices (macroscopic and microscopic) in the octopus O. maya also examined. Since the process of sexual maturation and gonad development in octopus has a hormonal control, finally this chapter shows the relationship between hormones (progesterone and testosterone) with the reproductive cycle of O. maya.

Cite as: Avila-Poveda OH (2014) Desarrollo gonádico, ciclo reproductivo y perfiles de progesterona y testosterona gonadal de Octopus maya Voss y Solís-Ramírez, 1966, a lo largo de su historia de vida: neonato, juvenil, subadulto y adulto. Ph.D. thesis. División de estudios de postgrado, Universidad del Mar, Puerto Ángel.