Cheilodipterus novemstriatus

Cheilodipterus novemstriatus
Name in bold Accepted name (May 2016) 1 Apogon novemstriatus Rüppell Cheilodipterus novemstriatus 2 Apogon bifasciatus Rüppell Apogonichthyoides taeniatus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Apogonidae
Genus:	Cheilodipterus
Species:	C. novemstriatus
Binomial name
Cheilodipterus novemstriatus (Rüppell, 1838)
Synonyms[1]
Apogon novemstriatus Rüppell, 1838 Cheilodipterus bipunctatus (Lachner, 1951) Paramia bipunctata Lachner, 1951

Cheilodipterus novemstriatus, the Indian Ocean twospot cardinalfish, is a species of ray-finned fish from the Indian Ocean, which is a member of the family Apogonidae. It has colonised the eastern Mediterranean Sea by way of the Suez Canal since 2011.

Description

Cheilodipterus novemstriatus has a slender body with a short snout, a terminal mouth which has canine-like teeth in both jaws. although there are no teeth at the symphysis of the lower jaw, and a large eye. There are two dorsal fins, the origin of the first dorsal fin is slightly behind the origin of the pelvic fin. The anal fin is in line with the second dorsal fin and the caudal fin is forked. The body is an overall silver-grey in colour with five contrasting, longitudinal black stripes with the upper running near the base of the dorsal fin. The middle or third stripe starts at the snout running through the eye to the caudal peduncle, while the lower stripe runs along ventral surface in an arc which terminates in front of the base of the pectoral fin, the portion of this stripe often becomes indistinct towards the base of the anal fin. The caudal peduncle has a large oval black spot which is surrounded by yellow background on the caudal peduncle and a second black spot is located on the dorsal surface of caudal peduncle.^[2][3] It is a small species reaching a maximum length of 8 centimetres (3.1 in) but more commonly measures 2–6 cm (0.79–2.36 in) in length.^[2]

Distribution

Cheilodipterus novemstriatus is native to the western Indian Ocean from the Red Sea to the Persian Gulf.^[3] In 2011 it was recorded in the Mediterranean Sea off Israel, then in Lebanon in 2012 and off south eastern Turkey in 2014, it is now established in the Levantine Sea, the most likely route for this invasion is by Lessepsian migration from the Red Sea via the Suez Canal.^[4]

Biology

Cheilodipterus novemstriatus is describes as common in shallow, sheltered waters^[3] and is found at depths of 1-10m over rocky reefss or coral which have holes and ledges. It will shelter among the spines of sea urchins of the genus Diadema in groups of as many as 30 individuals, although this depends on the relative sizes of the urchin to that of the fishes. It has also been recorded from a shipwreck at a depth of 30m in the Mediterranean, where it was sympatric with the indigenous Mediterranean cardinalfish Apogon imberbis, it has also been recorded on hard substrates covered with calcareous algae, near rocky crevices and overhangs. It has been recorded sheltering alongside juveniles of the native wrasse Coris julis.^[5]

Cheilodipterus novemstriatus is nocturnal and emerges from its daytime shelters to feed in more open areas, its nocturnal habits may have facilitated its successful invasion of the eastern Mediterranean as there are few indigenous nocturnal competitors. Its main food is zooplankton and in the Red Sea it is frequently encountered at night along sandy shores at depths of 0.5-1.5 m. It is a sociable species and gathers in large groups, especially in its daytime shelters and even in the newly established Mediterranean populations large schools have been encountered.^[2] Like other species of cardinal fish C novemstriatus show pairing behaviour and courtship and the male broods the eggs in his mouth.^[3]

References