A Tale of Two Urchins - Implications for In-Situ Breeding of the Endangered Banggai Cardinalfish (Pterapogon kauderni)

Abstract

Samliok Ndobe, Jamaluddin Jompa and Abigail Moore. 2018. A Tale of Two Urchins-Implications for In-Situ Breeding of the Endangered Banggai Cardinalfish (Pterapogon kauderni). Aquacultura Indonesiana, 19 (2): 65-75. The endangered Banggai cardinalfish Pterapogon kauderni, endemic to the Banggai Archipelago in Central Sulawesi, Indonesia, is a national and global priority conservation species. To support stock recovery based on in-situ breeding, using the symbiosis between the Banggai cardinalfish and its microhabitat (especially urchins of Genus Diadema), specific research objectives were: (i) identify the Diadema species associated with Banggai cardinalfish in the wild; (ii) investigate Banggai cardinalfish preference between these Diadema species. Belt transect data (5 sites) found wild Banggai cardinalfish of all size classes associated with Diadema setosum and Diadema savignyi. Preference trials were conducted in a controlled environment (concrete tanks) with three replicates. Nine sub-adult Banggai cardinalfish (35-42 mm SL), 12 D. setosum and 12 D. savignyi were placed in each tank. Banggai cardinalfish association (D. savignyi, D. setosum, none) was recorded hourly (06:00-18:00) for three days and results analysed in RStudio-1.0.143. Banggai cardinalfish did not show significant preference for either D. savignyi or D. setosum. These results indicate that D. savignyi and D. setosum can be used impartially in further research on in-situ breeding to facilitate recovery of Banggai cardinalfish stocks. However stock recovery measures should consider genetic connectivity and the natural balance between the two urchin species.

Monitoring the endemic ornamental fish Pterapogon kauderni in Bokan Kepulauan, Banggai marine protected area, Indonesia

“…The importance of diadematid sea urchins is reflected in local names such as the Bajo bebese tayung meaning small sea urchin fish (Ndobe et al, 2005). At least two (Ndobe et al, 2018b) and possibly more (Moore et al, 2019a) species of the genus Diadema serve as P. kauderni microhabitat. Association of P. kauderni with the genus Echinothrix also appears to be relatively common (Moore, 2019;Moore et al, 2019a;Ndobe et al, 2013aNdobe et al, , 2018b, while association with Astropyga has been reported when this genus was present (Moore, 2019;Moore et al, 2019a;Ndobe et al, 2018b;Talbot et al, 2013).…”

New host record of microhabitat preferences of the Banggai cardinalfish (Pterapogon kauderni) in the introduced habitat in Luwuk waters, Sulawesi

“…Clownfish usually throw other fishes from approaching sea anemones they live in, including the adult of Banggai cardinalfish; however, they tolerate the presence of juvenile [13]. There is much evidence that microhabitats, sea urchin, sea anemone, and hard coral life forms are important to support the Banggai cardinalfish populations [40,48,49]. The main factor in decreasing the Banggai cardinalfish population is the abundance of microhabitat populations, especially sea urchin and sea anemone [50].…”

“…This microhabitat associate has less information before. Little information about this association has been mentioned before, but a more indepth study has not been carried out [48]. The association between a small number of individual Banggai cardinalfish and jellyfish was recorded in Tinakin Laut, one of the research sites in the Banggai Islands.…”

Microhabitat association and population status of the Luwuk introduced Banggai cardinalfish (Pterapogon kauderni Koumans, 1933) population

“…These introduced populations cannot be classified as "benign introductions" under IUCN (2012) criteria, most seem to qualify as "wild subpopulations resulting from introductions outside the natural range" which should be assessed (IUCN, 2019). Their potential for contributing to conservation of the species is limited due to genetic diversity conservation issues (Ndobe et al, 2018a) Nonetheless, to date only one introduced population (Lembeh Strait, North Sulawesi) is reported as invasive and potentially detrimental to native species (Carlos et al, 2014;Erdmann and Vagelli, 2001;Vagelli, 2011), while several introduced populations have contributed to research on P. kauderni biology and ecology (Moore et al, 2020a(Moore et al, , 2020bNdobe et al, , 2013cNdobe et al, , 2013dNdobe et al, , 2018bSyahril et al, 2020).…”

“…Diadematid sea urchin microhabitat includes Diadema setosum, D. savignyi, and possibly D. clarki as well; Echinothrix diadema and E. calamaris; and more rarely Astropyga sp. (Moore et al, 2019a;Ndobe et al, 2013bNdobe et al, , 2020Ndobe et al, 2018b;Talbot et al, 2013;Wiadnyana et al, 2020).…”