Figure 1. Culture of bacteria (Pseudomonas sp.??) on marine agar isolated from larval rearing tanks at OI.Aloha everyone!It’s been a while since my last post, but it’s been a busy few months. Though it's the kind of busy you don't realize until you sit down and catch your breath. It’s been a lot of fun spending my days in the lab working with everyone learning new things. Figure 2. Sample of Parvocalanus nauplii on TCBS agar that was fed to yellow tang larvae. Since we are still observing relatively high mortality just past first feeding, my work at the Oceanic Institute is focused on bacterial population analysis and application of probiotics to our yellow tang larval rearing tanks. The first month of summer was spent looking at the growth of our live feeds with the addition of probiotics, which appear to have no effect on their survival or growth. This is great news for us
Larval development of yellow tangs from 15 to 50 days posthatch (dph). Photo credit: Dean Kline and David Hoy. Research on culturing yellow tangs began at the Oceanic Institute (OI) back in 2001 around the same time as initial, exciting breakthroughs were achieved with dwarf angelfish (by OI and others like Frank Baensch and Karen Brittain). It seemed, back then, that we were just around the corner from some major steps forward with the culture of previously thought “impossible to rear” species. Indeed, there has been incredible progress with the culture of marine ornamentals since that time. However, yellow tang have proven to be far more difficult to rear than many of the other targeted marine ornamental fish species under investigation. More than a decade later, we are finally seeing some exciting progress with rearing this species and will share updates about our work on this site. On Jan 1, 2014 we stocked a 1000L tank with about 40,000 yellow tang eggs. In this rearing attempt we experimented with very high water turn-over rates, and very clean (ultra UV dose) water. As in previous studies, we again used the calanoid copepod, Parvocalanus crassirostris, as our feed. While this was only one tank (we are currently testing these methods again), we immediately noticed far more fish making it through the early larval period than ever before. We were really excited to see 1000’s of fish making past the first 2-3 weeks and ended up with more than 600 at day 35. We have since moved the fish to smaller tanks and are investigating potential settlement cues, like photoperiod and substrate. The fish recently crossed day 50 and appear to be looking very close to settlement. We’re observing fairly high mortality during this period of transition, but still have more than 150 fish distributed among our tanks. We are hoping at least a few make it through, but regardless are very encouraged by this recent progress! With newly obtained support from Rising Tide Conservation and the Hawaii Tourism Authority, we are looking forward to pushing this culture technology forward. This work will be supported by an HPU graduate student (Emma Forbes) who will introduce herself in a separate post. Stay tuned for updates from OI and Emma!
Paracheilinus rennyae, endemic in the waters of Komodo National Park. Image by Mark Erdmann, Conservation International. Although best-known as the home of the world’s largest living lizard, Komodo National Park in the Lesser Sunda Islands of Indonesia is also a noteworthy dive destination that attracts biodiversity researchers doing marine species surveys in the Coral Triangle. One of those scientists, Dr. Mark Erdmann of Conservation International, has found and described a gloriously pigmented new species of Flasher Wrasse, Paracheilinus rennyae. The fish, distinguished by its rounded dorsal, anal, and caudal fins, is named in honor of Renny Kurnia Hadiaty from the Indonesian Institute of Sciences (LIPI) and in recognition of her scientific contributions to Indonesian fish taxonomy. Erdmann, Conservation International’s (CI) senior adviser to the Indonesian Marine Program, says that Renny’s Flasher Wrasse is endemic to East Nusa Tenggara, the province in southeastern Indonesia where Komodo Island National Park is located. Conservationists are hopeful that such discoveries will help protect such areas from development. Northern tip of Komodo Island, home to a living “dragon” and a diversity of marine life. “East Nusa Tenggara has more endemic species of flasher wrasses, which will hopefully encourage more tourists to come to Indonesia, since they can only see the endemic species here, including the new flasher wrasse,” Erdmann said on Wednesday. According to Erdmann, the first picture of a new, unknown wrasse was taken by a diver in Nusa Tenggara Timor (NTT) in 2010. “When the diver showed us the picture, we assumed it was a new species of flasher wrasse. Scientists from Udayana University [in Bali] later confirmed the species was genetically distinct from other flasher wrasse species,” he said. Following collaboration between scientists from Udayana University, Papua State University in Manokwari, Diponegoro University in Semarang, University of California, Los Angeles (UCLA) and Conservation International Indonesia, a description of the new species by Dr. Gerald Allen, Dr. Erdmann, and Ni Luh Astria Yusmalinda was published in the year-end edition of aqua, International Journal of Ichthyology. Popular among reef aquarium keepers and divers alike, flasher wrasses are known for their gaudy mating displays, in which the males flare their fins and “flash” electric-blue colors to attract females and initiate spawning events. Paracheilinus rennyae is genetically distinct from other known flasher wrasses in the Coral Triangle, with its closest relative being Paracheilinus angulatus from East Kalimantan, Brunei, Sabah and the southern Philippines. “The Maritime Affairs and Fisheries Ministry is increasingly aware of the need to generate more revenue from underwater tourism due to the country’s marine biodiversity, rather than solely depending on fishing,” Erdmann said. “But we haven’t yet calculated the value of these endemic flasher wrasse to NTT’s tourism,” he continued. Sources Jakarta Post Image, Northern tip of Komodo Island: Jon Hanson/Wikipedia/Creative Commons Abstract Gerald R. Allen, Mark V. Erdmann and Ni Luh Astria Yusmalinda: Paracheilinus rennyae, a new species of flasherwrasse (Perciformes: Labridae) from southern Indonesia, aqua, Volume 19, Issue 4 – 25 October 2013, pp. 193-206. The Indo-Pacific labrid fish Paracheilinus rennyae is described from four male specimens, 52.2-60.4 mm SL, collected in 15-21 m depth off southwestern Flores Island in the Lesser Sunda island chain of Indonesia. It is distinguished from most congeners by the lack of filamentous extensions of the dorsal fin rays in males and a rounded caudal fin margin, a combination of features shared only by P. octotaenia (Red Sea). It differs from the Red Sea species in having 13-14 rakers (vs. 16-18) on the first gill arch and several colour pattern differences. Genetic analysis (CO1) indicates it is closely related to P. angulatus from the Philippines and northern Borneo (Brunei, Sabah, and Kalimantan), but the two species exhibit marked differences in the shape of the median fins.