Galaxea, Journal of Coral Reef Studies 18: 1-2（2016）

Photogallery

Xestospongia testudinaria nighttime mass spawning observation in Indonesia

Till RÖTHIG* and Christian R VOOLSTRA

Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia

* Corresponding author: Till Röthig E-mail: [email protected]

Communicated by Frederic Sinniger (Editorial Board Member)

Keywords Xestospongia testudinaria, , spawning, Indo-Pacific

The marine barrel sponge Xestospongia testudinaria (Lamarck, 1815; Demospongiae; ) has a wide distribution in the Indo-Pacific according to the, World Porifera, database (van Soest 2008). Its size and oftentimes exposed habitus makes it a prominent member of the benthic communities. In Indonesian waters, a mass spawning event of this has been previously described for the Banda Sea (Sarano 1990). The author described a synchronized event in the morning hours of 29th of August 1989 (one day before new moon) in which X. testudinaria specimens released clouds of gametes into the water column. Further spawning has been observed early in the year 2012, but no details have been reported (Swierts et al. 2013). Another species from the same genus, Xestospongia muta has been observed to release eggs and sperm from 8.00h to 9.00h on March 30, 2004 in Belize (Ritson-Williams et al. 2005). Similarly, a synchronous mass spawning event took place at Gili Lawa Darat (8°28′30″S, 119°33′0″E) in the Northern Komodo National Park. Conversely to previous reports, we observed onset of a spawning event starting at dusk on the

Fig. 1 (A) Smooth and (B) lamellate morphotype of Xestospongia testudinaria releasing gametes into the water column. 2 Röthig and Voolstra: Sponge mass spawning observation

8th of July 2015, 6 days after full moon. We found numerous specimens of X. testudinaria releasing milky clouds of positively buoyant male gametes between 18.30h and 19.30h at depths between 10 to 20 m. There was a mild current and water temperatures were 28℃. We identified different morphotypes to spawn at the same time in close proximity (Fig. 1A, 1B). We could not find any signs of sponge spawning in the previous or following days. Swierts et al. (2013) hypothesized that stable water temperatures may allow the sponge to spawn during the whole year, but differences in spawning need to be identified. Comparison of the observations reported in here and in Sarano (1990) may indicate a similar spawning rhythm as reported for the same species in the Great Barrier Reef, where Fromont and Bergquit (1994) found a semilunar periodicity. They reported spawning in two consecutive years two days after full moon and in the third year one day before new moon.

Acknowledgments We thank Mermaid Liveaboards (Bali, Indonesia) for field support. We are grateful for the photo contribution from Alex Lindbloom.

References Fromont J, Bergquist PR (1994) Reproductive biology of three sponge species of the genus Xestospongia (Porifera: Demospongiae: Petrosida) from the Great Barrier Reef. Coral Reefs 13 (2): 119-126 Ritson-Williams R, Beccero MA, Paul VJ (2005) Spawning of the Xestospongia muta in Belize. Coral Reefs 24 (1): 160 Sarano F (1991) Synchronised spawning in Indonesian . Coral Reefs 10 (3): 166-166 Swierts T, Peijnenburg KTCA, de Leeuw C, Cleary DF, Hörnlein C, Setiawan E, Wörheide G, Erpenbeck D, Voogd NJ (2013) Lock, stock and two different barrels: comparing the genetic composition of morphotypes of the Indo-Pacific sponge Xestospongia testudinaria. PLoS ONE 8 (9): e74396 van Soest R (2008) Xestospongia testudinaria (Lamarck, 1815). In: Van Soest RWM, Boury-Esnault N, Hooper JNA, Rützler K, de Voogd NJ, Alvarez de Glasby B, Hajdu E, Pisera AB, Manconi R, Schoenberg C, Janussen D, Tabachnick KR, Klautau M, Picton B, Kelly M, Vacelet J, Dohrmann, M, Díaz MC, Cárdenas P (2015) World Porifera database. Accessed at http://www.marinespecies.org/porifera/porifera.php?p=taxdetails&id=166902 on 2016-01-24

Received: 1 October 2015/Accepted: 29 January 2016 Ⓒ Japanese Coral Reef Society