Life-cycle of Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae) with the morphological descriptions of the nauplius, copepodid and adult male.

Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae), an associate of the scyllarid lobster Ibacus novemdentatus Gibbes, was found to pass through at least four developmental stages: nauplius, copepodid I (CI), copepodid II or later (CII+) and adult. Free-living nauplii were observed hatching from the ovisacs of adult females. CI was found on the body surface of both female and male hosts, whereas CII+ and adult were obtained from the female host's egg masses. The life-cycle of this copepod is presumed to be as follows: (i) nauplius develops into CI in the water column; (ii) infective CI settles on body surface of host; (iii) CI moults into the following stage, changing its microhabitat from host's body surface to egg masses; (iv) CII+ develops on egg masses of host until adult stage; and (v) adult female and male mate on the host's egg masses.

Choniomyzon inflatus n. sp. (Crustacea: Copepoda: Nicothoidae) associated with Ibacus novemdentatus (Crustacea: Decapoda: Scyllaridae) from Japanese waters.

A new species of parasitic copepod, Choniomyzon inflatus n. sp., is described based on specimens collected from the external egg masses of the smooth fan lobster Ibacus novemdentatus Gibbes captured in the North Pacific Ocean off Ainan, Ehime Prefecture, western Japan. The new species differs from its congeners in having a globular to ovoid prosome, in bearing asymmetrically arranged denticles at a rounded apex of both the terminal segment of the antenna and the maxilliped, and in lacking serrate lobes on the basis of legs 1 and 2. The species is similar in size and shape to the host's eggs, which may be interpreted as egg mimicry. The new species is the first member of Choniomyzon Pillai, 1962 from subtropical regions.