Field Test on Breeding Technique of the Zoogamy for Acropora tumida

Abstract

Field Test on Breeding Technique of the Zoogamy for Acropora tumidaFumihito IWASE, Susumu NAKANO, Hiroshi AKI, Naoya OKADA and Rika SHIMIZU This study is aimed for establishment of the breeding technique by the zoogamy of Acropora tumida. The natural restoration works for coral communities has been carried out in the Takegashima underwater park located in Southeast Shikoku. A breeding by the zoogamy is effective for the restoration of the coral. Therefore we conducted field works about the growth process of this coral from eggs to juveniles. As a result of investigation of three years, we obtained some important ecological characteristics of this coral, such that laying eggs occurs about on July 3 in lunar calendar.

High Clonality and Geographically Separated Cryptic Lineages in the Threatened Temperate Coral, Acropora pruinosa

“…Clonal Structure, Genetic Diversity and Connectivity of A. pruinosa A high ratio of asexual reproduction was found in A. pruinosa. Despite the similar habitats and sexual reproductive biology with A. hyacinthus and A. solitaryensis (Iwase et al, 2009), A. pruinosa showed a higher ratio of asexual reproduction than A. hyacinthus (Nakabayashi et al, 2019) and A. solitaryensis (Noreen et al, 2013). It is likely that coral growth form is associated with the ratio of asexual reproduction; the arborescent growth form is more fragile to environmental factors than the corymbose or tabular form (Wallace, 1999).…”

“…Acropora pruinosa has a more limited genetic connectivity than other Acropora species, such as Acropora digitifera (Nakajima et al, 2010), A. solitaryensis (Noreen et al, 2013), and A. hyacinthus (Nakabayashi et al, 2019), despite having a similar early life ecology and the same larval dispersal duration (Iwase et al, 2009) to these species. It is possible that the arborescent morphological character, associated with a high frequency of asexual reproduction (fragmentations) of A. pruinosa, might be responsible for the limited genetic connectivity among populations.…”

“…After fertilization of gametes in the water column, larvae of A. pruinosa move to the surface and float in the ocean for 3-10 days before settling on the ocean floor (Iwase et al, 2009). Larvae of A. pruinosa have a high settlement rate, and usually settle on places slightly exposed to sunlight (Iwase et al, 2009). The overall early life ecology is quite similar to that of other Acropora spp.…”

“…This coral species releases its gametes into the water column once a year in summer, approximately 106 ± 10 min after sunset (Suzuki and Fukami, 2012). After fertilization of gametes in the water column, larvae of A. pruinosa move to the surface and float in the ocean for 3-10 days before settling on the ocean floor (Iwase et al, 2009). Larvae of A. pruinosa have a high settlement rate, and usually settle on places slightly exposed to sunlight (Iwase et al, 2009).…”

“…The overall early life ecology is quite similar to that of other Acropora spp. (Iwase et al, 2009) and it exhibits genetic connectivity among different populations (e.g., Nakabayashi et al, 2019).…”