Ovarian Morphology of the Female Bluebanded Goby
Abstract
In female vertebrates, the ovarian cycle has distinct stages indicating follicular and oocyte development; however, the mechanisms and morphology of these stages are relatively unknown. The purpose of this study is to better characterize the ovarian cycle in a marine fish. Bluebanded goby, Lythrypnus dalli, are hermaphroditic bidirectional sex changing fish. We used external morphology of the abdomen to estimate their gravidity and also examined the length and width of the genital papilla, before their ovaries were extracted. We categorized the ovaries of the female into four different phases and within each phase there were 5 stages of the follicles within the ovary. The whole ovaries were collected at each phase then placed in paraformaldehyde to preserve them. They were then rehydrated, sectioned, H&E stained then imaged with a microscope. This process allowed us to visualize follicles for measurement and quantification. We then compared ovarian stages in each phase to see which follicles states were most present in each. We expected to find the early stages in the early phases and the late stages in the late phases. We found that there were more later stage (5) follicles in phase 4 ovaries (most ripe) and none of the follicle stage 5 in phase 1 (early stage). Phases 2 and 3 shared some similarities and could almost be quantified as one phase. Further research is required to understand the reason for the relation of the ovarian follicles to the ovarian phases in the female goby.
Ovarian Morphology of the Female Bluebanded Goby
In female vertebrates, the ovarian cycle has distinct stages indicating follicular and oocyte development; however, the mechanisms and morphology of these stages are relatively unknown. The purpose of this study is to better characterize the ovarian cycle in a marine fish. Bluebanded goby, Lythrypnus dalli, are hermaphroditic bidirectional sex changing fish. We used external morphology of the abdomen to estimate their gravidity and also examined the length and width of the genital papilla, before their ovaries were extracted. We categorized the ovaries of the female into four different phases and within each phase there were 5 stages of the follicles within the ovary. The whole ovaries were collected at each phase then placed in paraformaldehyde to preserve them. They were then rehydrated, sectioned, H&E stained then imaged with a microscope. This process allowed us to visualize follicles for measurement and quantification. We then compared ovarian stages in each phase to see which follicles states were most present in each. We expected to find the early stages in the early phases and the late stages in the late phases. We found that there were more later stage (5) follicles in phase 4 ovaries (most ripe) and none of the follicle stage 5 in phase 1 (early stage). Phases 2 and 3 shared some similarities and could almost be quantified as one phase. Further research is required to understand the reason for the relation of the ovarian follicles to the ovarian phases in the female goby.