C. parasema, from Komodo. Credit: 55mermaid
“Yellowtail Damselfish” C. parasema
- Range: Philippines north to the Ryukyu Islands, south to Sabah, Java Sea, Flores
- Etymology: Greek “streamer”, allegedly in reference to the pale tail
- Size: 5cm
- Aquarium Rarity: Abundant
- ID: Entirely blue, except for a bright yellow caudal fin and peduncle.
Notes: Originally described in 1918 as Abudufduf parasema. This species ranges further north than any other in its complex, reaching the Amami Islands of Japan, but apparently unknown from the main islands. It’s difficult to theorize why this species should be found here, but not some of the other Philippine populations (e.g. cf springeri & oxycephala).
C. hemicyanea, aquarium specimen. Credit: Aquarent
“Azure Damselfish” C. hemicyanea
- Range: Bali, Southern Sulawesi, east to Raja Ampats and Kei Islands
- Etymology: Greek “half dark-blue”
- Size: 5cm
- Aquarium Rarity: Common
- ID: Yellow ventrally from the throat to the anterodorsal corner of the caudal peduncle, and all the encompassed fins.
Notes: Also known as the “Royal Damselfish”… neither common name is particularly informative. The only species in this complex authoritatively documented from Western Australia.
C. giti at Lembeh, an apparent range extension. Credit: Masamichi Torisu & risingmoon
“Giti Damselfish” C. giti
- Range: Northern Sulawesi (Togean Islands & Lembeh) and Sebakor Bay, Fak Fak Peninsula, New Guinea
- Etymology: Named after Giti Tire, a Singapore-based tire manufacturer, whose owners placed a winning bid during an auction to name the species. Proceeds went towards conservation efforts in the region.
- Size: 5cm
- Aquarium Rarity: Absent
- ID: Yellow restricted caudally and in anal fin
Notes: Only described in 2008, this species is a perfect intermediate between parasema and hemicyanea. A detailed genetic study is warranted to help in understanding its evolutionary origins, and whether it might be of hybrid derivation. It is known to hybridize with C. arnazae at Lembeh (see below). Aquarium specimens are unknown, but collection does take place in parts of its range.
C. arnazae seen at Lembeh. Credit: Masamichi Torisu
“Arnaz’s Damselfish” C. arnazae
- Range: Flores, Lembeh, Halmahera, Raja Ampats, east to Madang and Bismarck Archipelago
- Etymology: After Arnaz Mehta, wife of Dr. Mark Erdmann, one of the authors.
- Size: 5cm
- Aquarium Rarity: Uncommon
- ID: yellow extending posterior to anal fin origin, as well as pelvic fins
Notes: Described in 2010, this uncommonly collected species is sometimes seen as the Half-blue Damselfish—a confusing choice given the etymology of hemicyanea.… More:
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