The reproductive ecology of the invasive ascidian, Styela clava, in Auckland Harbour, New Zealand

From Tropical to Sub-Tropical: Prolonged Reproductive Activity of the Invasive Ascidian Microcosmus exasperatus in the Eastern Mediterranean

“…Moreover, the significant variance in oocyte diameter among individuals implies that different developmental stages can be found concomitantly in the same month: e.g., while some individuals were at a mature stage, others were redeveloping gonads. Multiple developmental stages of the gonads were also reported in populations of the invasive ascidian Styela clava in Ireland (Parker et al, 1999), New Zealand (Wong et al, 2011), and Canada (Davidson et al, 2005). Considering the tendency of M. exasperatus to form large aggregations (Shenkar and Loya, 2009;Nagar and Shenkar, 2016), it is possible that the asynchronous development of the gonads provides a mechanism for avoiding self-fertilization of the population, as suggested by Wong et al (2011) for a Styela clava population in New Zealand.…”

“…As emphasized previously (Becerro and Turon, 1992;Bingham, 1997;Wong et al, 2011), the GI alone is not a sufficiently accurate parameter by which to evaluate reproduction activity. GI changes can also derive from the accumulation or reduction of nutritive tissues in the gonads.…”

“…Food availability too is known to have an important influence in regulating reproduction cycles in ascidians (Yamaguchi, 1975;Bingham, 1997;Wong et al, 2011), and low concentrations of food availability can even lead to gamete absorption and restrict reproductive activity (Goodbody, 1961;Berrill, 1975). Nonetheless, it was found in Potter Cove, Antarctica, that the solitary ascidian Cnemidocarpa verrucosa reproduces in the winter months, which are considered as the months with the lowest energy availability of the year (Sahade et al, 2004).…”

Effects of temperature and body size on the physiological energetics of the stalked sea squirt Styela clava

“…The solitary ascidian Styela clava (Herdman, 1882), native to the Sea of Okhotsk, the East/Japan Sea and the coasts of Japan, Korea, and northern China, has spread widely to many localities worldwide including the east and west coasts of North America, Europe, and the southern hemisphere, including Australia and New Zealand (Clarke and Therriault, 2007;Lützen, 1999;Wong et al, 2011). This ascidian has become one of the world's successful invasive species and sometimes replaced other indigenous ascidian populations with lower densities of 50-100 individuals m − 2 on natural substrates and 500-1000 individuals m − 2 on artificial substrates (Lambert and Lambert, 1998;Lützen, 1999).…”

Reproductive biology of Ophiocoma aethiops and O. alexandri (Echinodermata: Ophiuroidea) from Estacahuite Bay, Oaxaca, Mexico

“…For a number of marine invertebrates, reproductive biology is one of the most important traits in their life history (Stancyk 1979, Avila-Poveda 2004, Benítez-Villalobos 2005, Grange 2005, Wong et al 2011, and research indicates that it changes with latitude and according to environmental factors (Pearse 1968, Bower et al 2002, Guest et al 2005, Mercier & Hamel 2009). In marine invertebrates, large spatial scales generate diverse reproductive patterns (Roy et al 1998, Ramirez-Llodra 2001, Bower et al 2002, AvilaPoveda & Baqueiro-Cardenas 2009, Benítez-Villalobos & Díaz-Martínez 2010.…”