Development of <i>Carybdea brevipedalia</i> Kishinouye, 1891 (Cnidaria: Cubozoa: Carybdeida: Carybdeidae) collected from northern Japan

Abstract

Envenomation by toxic box jellyfish species is known to be a serious problem to public health. In order to elucidate the problem, it becomes necessary to predict the occurrence of box jellyfishes, as well as understanding their ecology and life cycle. Mature medusae of Carybdea brevipedalia (Cubozoa: Carybdeida), which is a common species of box jellyfish in Japan, were collected from northern Japan to observe its early life history, including polyp formation. Fertilization occurred externally, and blastulae developed into planulae. Free swimming planulae settled and metamorphosed into tiny primary polyps with two forms, i.e. settled and creeper. Adult polyps formed cysts at temperatures below 15°C or when water replacement and/or feeding was stopped. Budding occurred in four-tentacled polyps, and the buds were released after commencement of budding. Complete metamorphosis of a whole polyp into a single medusa occurred at stable temperatures between 18 to 25°C (18, 20, 23, 25°C, respectively) or when temperatures were raised from 20 to 25°C. Newly released medusae had four tentacles. Our study demonstrated that polyps of C. brevipedalia survive and propagate over a wide range of water temperatures and that developmental features resemble closely those of some tripedaliid species, namely Tripedalia cystophora and Copula sivickisi, rather than Carybdea marsupialis. The morphological affinities of polyp in C. brevipedalia, T. cystophora and C. sivickisi support recent molecular results. However, further studies are needed to confirm the morphological contradiction between C. brevipedalia and C. marsupialis in the future.

Early life history and metamorphosis in <i>Malo maxima</i> Gershwin, 2005 (Carukiidae, Cubozoa, Cnidaria)

“…This description of the life history of both sessile and motile stages of the tropical Australian carybdeid Malo maxima is contrary to those of the majority of presently described Cubozoa, which include planula with pigmentation bands (Widersten 1968, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Hartwick 1991a, Hartwick 1991b, Nordström et al 2003, Carrette et al 2014, Toshino et al 2014a, Toshino et al 2014b, Straehler-Pohl 2017, creeping polyps (Werner et al 1971, Werner 1975, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Werner 1983, Hartwick 1991a, Straehler-Pohl & Jarms 2005, Adler & Jarms 2009, Straehler-Pohl 2009, Straehler-Pohl & Jarms 2011, Carrette et al 2014, Kingsford & Mooney 2014, Toshino et al 2014a, Toshino et al 2014b, and the complete metamorphosis of a single polyp into a single, fully-formed, free-living medusa with no remaining regenerative residuum (Werner et al 1971, Studebaker 1972, Cutress & Studebaker 1973, Werner 1973b, Arneson & Cutress 1976, Werner 1976, Yamaguchi & Hartwick 1980, Werner 1983, Laska-Mehnert 1985, Nordström et al 2003, Straehler-Pohl & Jarms 2005...…”

“…The main body structure of Malo maxima polyps is similar to that of all presently described cubopolyps (Werner et al 1971, Studebaker 1972, Cutress & Studebaker 1973, Werner 1973a, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Straehler-Pohl 2009, Carrette et al 2014, Courtney et al 2016, Straehler-Pohl 2017, Straehler-Pohl & Jarms 2011, Toshino et al 2013, Toshino et al 2014a, Toshino et al 2014b, Toshino et al 2017. Additionally, M. maxima displays certain features shared with a limited number of cubozoan species such as multiple nematocysts in the tentacle tips (Werner et al 1971, Werner 1975, Chapman 1978, Toshino et al 2013, Toshino et al 2014a, Toshino et al 2017 and an association with zooxanthellae (Straehler-Pohl & Jarms 2011).…”

“…The planula of Malo maxima did not possess pigmentation spots associated with cubozoans outside the family Carukiidae (Widersten 1968, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Hartwick 1991b, Nordström et al 2003, Carrette et al 2014, Toshino et al 2014a, Toshino et al 2014b, Straehler-Pohl 2017. These spots are likely photoreceptors (Nordström et al 2003) and their absence in carukiids suggests that either orientation to or away from light may not play a major role in dispersal and/or settlement and that there may be additional sensory structures within the planula that determine direction of movement and substrate choice (Sinigaglia et al 2015).…”

“…The resulting secondary polyps are thus far unique to the family Carukiidae in their capacity to swim by beating cilia to propel themselves through the water column while extending one of their two tentacle tips in the direction of movement. An advantage of this method of swimming compared to the creeping observed in secondary polyps of other cubozoan families (Werner et al 1971, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Straehler-Pohl & Jarms 2005, Carrette et al 2014, Toshino et al 2014a, Toshino et al 2014b) may be that while the latter require a substrate on which to creep, the swimming carukiid polyps can move freely in the water column (Toshino et al 2013, Courtney et al 2016.…”

“…Cubozoans (there is presently debate about this nomenclature with the suggestion that the order Cubomedusae is the correct classification as per Straehler-Pohl 2017) are cnidarians, some of which are capable of causing lifethreatening envenomations (Bengston et al 1991, Suntrarachun et al 2001, Carrette et al 2012. Around 44-50 species of cubozoans have been described, however, the early life histories and asexual reproduction strategies of only a handful of species are known (Werner et al 1971, Studebaker 1972, Werner 1973b, Werner 1975, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Werner 1983, Hartwick 1991b, Carrette et al 2014, Toshino et al 2014a, Toshino et al 2014b, Courtney et al 2016, Toshino et al 2017. For the majority of species whose polyps and early developmental stages have been observed, the descriptions are remarkably similar: planulae settle on hard substrate and transform into a polypoid, sessile stage lacking inner anatomical structures (Werner et al 1971, Studebaker 1972, Arneson & Cutress 1976, Hartwick 1991b, Yamaguchi & Hartwick 1980, Laska-Mehnert 1985, Nordström et al 2003, Carrette et al 2014, Toshino et al 2014a, Toshino et al 2014b, Straehler-Pohl 2017; planulae display pigment spots in a banding pattern (Werner et al 1971, Studebaker 1972, Arneson & Cutress 1976, Yamaguchi & Hartwick 1980, Hartwick 1991b…”