The reproductive ecology of the invasive Asian paddle crab, Charybdis japonica (Brachyura: Portunidae), in northeastern New Zealand

Abstract

The Asian paddle crab, Charybdis japonica, native to the northwest Pacific, is an invasive species that has established populations within northeastern New Zealand. Here, we provide a detailed examination of C. japonica's reproductive seasonality and gametogenesis, sizes at physiological maturity, and sex ratios outside its native range. Trapping in the Weiti River Estuary, Whangaparoa (36°38.4 0 S, 174°43.6 0 E) from February 2010 to May 2012 indicated a male-biased population. Reproductive seasonality largely depended on female condition, since males contained ripe spermatozoa year-round. Female gametogenesis began during late autumn, with oocyte development occurring throughout winter to early spring. Based on the presence of mature gametes during late winter and the appearance of gravid females in early November, mating began during early spring, with spawning in mid-spring. Spawning coincided with a large drop in the gonad index, and occurred between sea surface temperatures of 17-22°C and 11.75-13.5 h day length. Females remained reproductive for up to 5 months of the year. Histological observation suggested that CW50 (the carapace width at which 50% of the population is mature) for females was 46.39 mm, while CW50 for males could not be determined due to a paucity of immature males. Histological analysis also suggested that females of C. japonica could produce store sperm and multiple broods annually.

Ultrastructure and histochemistry of the male reproductive system of the genus Callinectes Stimpson, 1860 (Brachyura: Portunidae)

“…hawaiiensis (Ryan, 1967), C . sapidus (Johnson, 1980), and Charybdis japonica (A. Milne‐ Edwards 1861) in Wong & Sewell (2015) and in the majoid Libinia spinosa Guérin, 1832 (Sal Moyano et al, 2010). However, in another majoid, M .…”

“…sapidus (Johnson, 1980), and Charybdis japonica (A. Milne-Edwards 1861) in Wong & Sewell (2015) and in the majoid Libinia spinosa Guérin, 1832(Sal Moyano et al, 2010. However, in another majoid, M. brachydactyla, cells are organized in germinal zones arranged opposite to the evacuation zone (seminiferous tubule lumen), that characterizes, the tubular-type testis (Simeó et al, 2009(Simeó et al, , 2010.…”

Sexual traits and reproductive strategy of the leucosiid crabPyrhila pisum

“…Among many brachyuran crabs, male crabs can guarantee mating success because of the short duration of the receptive female condition and avoidance of sperm competition using pre-or postcopulatory guarding (Hartnoll, 1969;Salmon, 1983;Christy, 1987;Diesel, 1991;Asakura, 2009). Thus energy investment into gonads is not so important for males compared with females, whose fitness is directly reflected by fecundity, and male gonads are much smaller than those of females (Kyomo, 1988;Kobayashi & Matsuura, 1995;Omori et al, 1997;Tsuchida & Watanabe, 1997;Chu, 1999;Liu & Li, 2000;Swiney & Shirley, 2001;Wong & Sewell, 2015). Only a potamid crab Potamon fluviatile (Herbst) has been reported as an exceptional case in which male gonads develop larger than female gonads (Michelli et al, 1990).…”

New records of Charybdis japonica (A. Milne-Edwards, 1861) (Crustacea: Decapoda: Portunidae) in the Adriatic Sea

“…Unlike most Portunid crabs, C. japonica adult females' mate in the hard-shell stage (BAKER et al, 2018;KOBAYASHI & VAZQUEZ-ARCHDALE, 2018), and store in the spermathecae viable sperms used to fertilize eggs in successive broods (WONG & SEWELL, 2015). In its native area and in New Zealand, spawning occurs in the warm season and the average fecundity is around 400,000 eggs per clutch (FOWLER & MCLEAY, 2013).…”