The first and third chalimus stages and chalimus adult (previously known as young adult) of Caligus latigenitalis are described based on new material collected from the body surface of a heavily infected wild blackhead seabream Acanthopagrus schlegelii schlegelii from Hiroshima Bay, Japan. The second and fourth chalimus stages of the same species are redescribed. Adults of C. latigenitalis are characterized by possessing 2 stout marginally indented processes at the base of 2 terminal spines at distal exopodal segment of leg 4. The chalimi were identified to stage based on the structure of the frontal filament and the discrete ranges in body length. Sexual dimorphism is first observed at the third chalimus stage in the shape of the distal segment of the antenna. The total number of postnaupliar stages of C. latigenitalis is 6, including 4 semaphoronts, i.e., 1 copepodid stage consisting of 1 infective copepodid and the chalimus copepodid, 4 chalimus stages, and 1 adult stage with 1 chalimus adult and 1 mobile adult. New terminology for the developmental stages of caligid copepods is proposed herein by amending the definition of chalimus as the postnaupliar stages, as well as semaphoronts having a frontal filament for host attachment.

In symbiotic copepods, most naupliar stages are typically planktonic, playing a primary role in dispersal, while the first copepodid usually represents the infective stage. Later copepodid stages, including adults, are associated with host organisms. Many symbiotic copepods have abbreviated life cycles, with a reduced number of naupliar stages and two

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A new nematode species, Capillaria acanthopagri n. sp. (Capillariidae), is described from the intestine of the marine fish (black porgy) Acanthopagrus schlegelii schlegelii (Bleeker) from coastal waters of the western north Pacific Ocean off Kochi, Shikoku Island, Japan. The new species, belonging to the subgenus Neocapillaria Moravec, 1987 , differs from other congeneric species of this subgenus from marine fishes (with the exception of C. navonae Timi, Rossin and Lanfranchi, 2006 ) mainly in the length (204-285 microm), shape, and structure of the spicule; and except for C. cooperi Johnston and Mawson, 1945, in markedly small body measurements (males and females 3-4 and 6-10 mm long, respectively). It is characterized by the presence of 33-43 elongate stichocytes; a heavily sclerotized spicule with rough transverse grooves; a spinous spicular sheath; and by eggs measuring 27-30 x 57-60 microm, without protruding polar plugs. Capillaria acanthopagri n. sp. is the first known species of Neocapillaria parasitizing fishes of the perciform Sparidae and the second species of this subgenus recorded from fishes of the Pacific Ocean.

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