Data from: The mating behaviour of the seed shrimp Parapolycope spiralis (Ostracoda: Cladocopina), with insight into the evolution of mating systems in cryptic interstitial habitats

The mating behaviour of the interstitial ostracod Parapolycope spiralis Tanaka & Tsukagoshi, 2010 is reported here for the first time. This species is adapted to an interstitial environment, and is typified by having tiny body size and being completely blind. In this paper it is presumed that the characteristics of the mating behaviour are typical for species in an interstitial environment. Observations by microscopy on mating behaviour in the laboratory showed various distinct stages: (1) the male captures the female by a sucker on the antennula; (2) the male clasps and maintains the mating position using the endopodite, the endopodite claw, and the exopodite of the antenna; (3) the male makes contact using the distal part of the upper lip; and (4) copulation takes place. These observations indicate that the sequence of stages of the mating behaviour of miniaturized animals is not necessarily always a simplified process. During the process, it seems that the male upper lip establishes physical contact stimuli with the female. Because the interstitial environment is cryptic and consists of a three-dimensional space with reduced connectivity, direct physical contact is likely to be one of the most effective and successful courtship behaviours.本研究首次报道间隙生境介形类（Ostracod）物种旋形副多介虫（Parapolycope spiralis，Tanaka & Tsukagoshi, 2010）的交配行为。该物种适应间隙生境，其典型特征为体型微小且完全丧失视觉能力。本文推测，其交配行为特征可作为间隙生境物种的典型模式。通过实验室显微观察该物种的交配行为，研究人员发现其可划分为多个清晰阶段：(1) 雄性以第一小触角（Antennula）上的吸盘捕获雌性；(2) 雄性借助触角的内肢（Endopodite）、内肢爪及外肢（Exopodite）固定并维持交配体位；(3) 雄性以上唇的远端区域与雌性接触；(4) 完成交配。上述观察结果表明，小型化动物的交配行为序列未必始终为简化过程。在此过程中，雄性上唇似乎会向雌性施加物理接触刺激。由于间隙生境具有隐蔽性，且由连通性受限的三维空间构成，直接物理接触可能是最为有效且成功的求偶行为之一。