Gender identification of shovelnose sturgeon using ultrasonic and endoscopic imagery and the application of the method to the pallid sturgeon

Abstract

Monthly sampling of shovelnose sturgeon Scaphirhynchus platorynchus, a biological surrogate for the endangered pallid sturgeon Scaphirhynchus albus, was conducted to develop a multiseasonal profile of reproductive stages. Data collected included histological characteristics of gonads from wild caught fish and laboratory and field ultrasonic and endoscopic images. These data were used to compare effectiveness of ultrasonic and endoscopic techniques at identifying gender of adult shovelnose sturgeon at different reproductive stages. The least invasive method (i.e. ultrasound) was least effective while the most invasive (i.e. endoscope through an abdominal incision) was the most effective at identifying shovelnose sturgeon gender. In most cases, success rate for identifying males was greater than females, with success at identifying both genders greater in more advanced reproductive stages. Concomitantly, for most months average reproductive stage was more advanced for males than females. April and May were the months with the most advanced reproductive stage, and were the months when ultrasound was most effective. Methods were also applied in the Upper Missouri River to validate their use on pallid sturgeon Scaphirhynchus albus. Ultrasound was successful at identifying pallid sturgeon gender, however, endoscopic examination through the urogenital duct was only successful at identifying pallid sturgeon gender when the urogenital duct was not opaque. # 2005 The Fisheries Society of the British Isles (No claim to original US government works)

Discovery and identification of candidate sex-related genes based on transcriptome sequencing of Russian sturgeon (Acipenser gueldenstaedtii) gonads

“…Because there is no external sexual dimorphism in the some sturgeon, for example, the Russian sturgeon, the development of internal gonads is the only biomarker for sex identification. So far, there are four different internal examination methods for sex identification in sturgeons, including invasive surgery (14,17,27), endoscopy (37), ultrasound (62), and measurement of biochemistry and hormone levels in the blood (4,9,21,47,50). The sex of sturgeons can be confirmed via an endoscopic system with very high accuracy (95%) (29).…”

“…The success rate for identifying males by ultrasound is greater than for females. Meanwhile, the accuracy of the ultrasound and endoscopic methods varies for different sturgeon species (62). Those methods, though successful in terms of accuracy, are harmful to the gonad and the body of the fish to different degrees and are not suited to immature sturgeon.…”

QUALIDADE DE GAMETAS COM A TÉCNICA DE ENDOSCOPIA EM CURIMBA (Prochilodus lineatus)

“…Em Medicina Veterinária ela é utilizada para examinar órgãos internos de peixes via inserção do endoscópio na cavidade celomática (Wildhaber et al, 2005).…”

“…Esta técnica tem se mostrado eficaz, e tem como vantagem o fato de não ser invasiva (Divers et al, 2009;Hernandez-Divers et al, 2004;Kynard e Kieffer, 2002). Comparando-se a eficiência entre o ultrassom e a endoscopia, foi constatada que quanto mais invasiva a técnica, maior será a facilidade de visualização, contribuindo, assim na determinação das características reprodutivas dos peixes (Wildhaber et al, 2005).…”

Reproductive condition and occurrence of intersex in bighead carp and silver carp in the Missouri River

“…Other reports of intersex in bighead or silver carps are unknown, but this is not the first report of intersex in fish from the Missouri River. Wildhaber et al (2005) documented a high incidence (7%) of abnormal hermaphroditism in shovelnose sturgeon collected from the Missouri River in 2001 and 2002. Although intersex in cyprinids has not been widely reported in the United States, Jobling et al (2002) have documented a high incidence of intersex in the roach Rutilus rutilus throughout the UK and associated this condition with sewage effluent contamination.…”