Copulation behaviour of Neptunea arthritica: baseline considerations on broodstocks as the first step for seed production technology development

Abstract

Copulation trials under three different scenarios were performed aiming to study the copulation behaviour of Neptunea arthritica and determine whether broodstock maintenance is required for artificial seed production. Neptunea arthritica showed polygamy, copulating at least three times with different partners. From all males and females used in this study, 43% of them copulated at least once. Female whelks showed rejection behaviour, which generated significant difference in copulation time between rejected (13.7±10.7 min) and non‐rejected (49.7±44.7 min) males. The effect of body size on copula duration appeared to be superficial, while its effect on accumulative copulas played an important role as an indicator of copulation capacity because whelks varied in size. After first copula, males showed a contrasting tendency to mate copulated females over non‐copulated females (χ2=6.23, d.f.=1, P=0.01). Broodstock maintenance as the first step in seed production is possible but considering low mating percentage and female rejection, it would be not economically reasonable due to the considerable number of whelks required and related logistical factors.

Influences of population density on polyandry and patterns of sperm usage in the marine gastropod Rapana venosa

“…In most neogastropods, sperm is first received in the copulatory bursa and then transferred over 3 days period to the seminal receptacle where storage and fertilization are thought to occur 46 47 . It is unknown how long ejaculates take to reach the seminal receptacle in R. venosa .…”

Sexual conflict inNeptunea arthritica: the power asymmetry and female resistance

“…Rejected (R) to non-rejected (NR) male proportion was recorded. Following Miranda et al (2008a), male whelks were considered as R while attempting copula, aborting further approach or withdrawing into its shell after mounting and/or during intromission, a product of female resistance. Males that could overcome resistance and finish intromission by their own timing were recorded as NR.…”

“…Additionally a test for male mate size preference was performed using copulated females (CF) from previous trials to eliminate confounding effects of male mating bias towards CF (Miranda et al , 2008a) or pheromone mediated attractiveness (Martel et al , 1986; Chase, 2002; Ilano et al , 2004). Trials consisted of one non-copulated male (NCM) with a pair of CF.…”

“…In the Neptune whelk, Neptunea arthritica (Bernardi), reproduction presumably imposes high costs to females due to reduced feeding opportunities, differential investment in gametes, egg capsules and embryonic allotments alongside predation risk during oviposition (Parker, 1978; Martel et al , 1986; Rowe, 1992; Rowe et al , 1994; Brokordt et al , 2003; Ilano et al , 2004). Males force mating, while females exhibit resistance by escape, pushing, biting and/or body swinging against copulation attempts as well as during intromission (Miranda et al , 2008a).…”

Reproductive characteristics and variations in the biochemical composition ofNeptunea arthritica cumingii crosse through embryonic development

“…Histological techniques have been used to study the microstructure and ultrastructure of the reproductive system of N. arthritica cumingii as well as the processes of spermatogenesis and oogenesis (Gao, 2008;Hou, Gao, & Zou, 2006). Lombardo and Goshima (2010) and Miranda, Lombardo, and Goshima (2008)…”