Confirmation of the presence of Heniochus acuminatus (Linnaeus, 1758) (Chaetodontidae) and Pomacanthus maculosus (Forsskål, 1775) (Pomacanthidae) in Iraqi marine waters, Arabian Gulf

Confirmation of the presence of Heniochus acuminatus (Linnaeus, 1758) (Chaetodontidae) and first record of Pomacanthus maculosus (Forsskål, 1775) (Pomacanthidae) in Iraqi marine waters, Arabian Gulf .— Two specimens (116,119 mm TL) of Heniochus acuminatus (Linnaeus, 1758) and four specimens (171–190 mm TL) of Pomacanthus maculosus (Forsskål, 1775) were collected from Iraqi marine waters of the Arabian Gulf. These findings confirm the presence of H. acuminatus and establish the first record of P. maculosus from Iraqi waters. The samples were captured by hook and line off the coasts of Al–Fao City Peninsula, southern Iraq. Arabian Gulf. morphometric and meristic data are provided and compared with data from other parts of the world.


Introduction
Members of the butterfly fish group are varied and abundant marine perciform fishes with remarkable coloration, d on reefs throughout shallow, tropical seas.Members of the Chaetodontidae family, noted for their colouration and body shape (Fessler & Westneat, 2007), have drawn the attention of scientists to study their taxonomy and biology (Ferry-Graham et al., 2001).There are ten genera and 117 species within the family Chaetodontidae (Allen & Erdmann, 2012).Chaetodon is the most diverse genus with 89 species.The genus Heniochus comprises eight species (Eschmeyer, 2014).
Due to their anatomical similarities, species of this family have been included within the family Chaetodontidae (Allen & Erdmann, 2012) but controversy has arisen on this issue.On the basis of molecular studies, the two families were considered sister taxa (Bellwood et al. 2004(Bellwood et al. , 2010)), but Near et al. (2013) and Hodge et al. (2013) consider that they are non-sister taxa as the nodes separating them in their phylogenetic tree have low support.
Although the marine fish fauna of Iraq has been documented in the last few decades (Khalaf, 1961;Mahdi, 1971;Al-Daham, 1982;Al-Hassan & Al-Badri, 1986;Al-Hassan & Miller, 1987;Hussain et al., 1988), the marine ichthyofauna is still far from being fully known and documented.A considerable amount of taxonomic work is waiting to be done (Jawad, 2012).Such delay in the progress of ichthyological investigation in the Iraqi marine waters is mainly due to the political unrest in the area.
Several programs have recently, been started to survey fish biodiversity in Iraqi waters of the Arabian Gulf.The aim is to build a list of species that are present in the northwest part of the Arabian Gulf.
The two species reported in the present study showed a narrow (P.maculosus) to wide range of distribution (H.acuminatus) (Froese & Pauly, 2014;Hodge et al., 2013).Both species have been recorded previously from the Arabian Gulf waters, but their presence in the Iraqi waters has not been published to date.This is an important record as it confirms the presence of both species in the Iraqi marine waters of the Arabian Gulf.So far, no other species within the genera Pomacanthus and Heniochus have been detected in this area.Although these two species have been recorded previously in Arabian Gulf waters, confirmation of these and any other coral reef associated species in local waters will support the present efforts of the Iraqi government to evaluate, protect and maintain the coral reef habitats in the Iraqi marine waters (Ali, 2013).The coral reef habitats were neglected from being a protected area and under consideration as a national park for the last decades (Mohammed, 2012).Therefore, the results obtained in the present study will be significant for the conservation of the coral reef habitats project in Iraq.

Studied material
On 21 st January 2014 two specimens of Heniochus acuminatus and four specimens of Pomacanthus maculosus (figs.1, 2) were caught by hook and line from the Fao City Peninsula, south of Iraq, Arabian Gulf.The morphometric and meristic details of the two species were recorded according to Fischer & Bianchi (1984) and are shown in table 1.The specimens were then fixed in 10% formaldehyde solution and preserved in 70% ethanol for deposit in the fish collection of the Marine Science Centre, University of Basrah, Iraq.
The specimens of the present two species are identical to the general description of these species (Randall, 1995).
H. acuminatus is characterised by the following set of characters: body deep and snout pointed; fourth dorsal spine very long; caudal fin truncate; body white with two pairs of diagonal black bands; snout and interorbital space black; caudal fin and posterior part of  dorsal fin yellow.It differs from Heniochus diphreutes in having 11 spines in the dorsal fin, more protruding snout length, triangular breast shape, and the 2 nd black band ending at the middle of the anal fin, versus 12 dorsal fin spines, less protruding snout, more rounded breast, and the 2 nd black band ending at the corner of the anal fin.
Pomacanthus maculosus has the following characters: body compressed; posterior margin of preopercle serrated with spines on ventral margin; posterior portion of dorsal and anal fins elevated with middle rays extended into a filament directed posteriorly; caudal fin rounded; body blue with irregular yellow bar in the middle with some dark curved markings running dorso-posteriorly on head and body; black, vertically elongated spots on posterior part of head and nape; posterior parts of dorsal and anal fins with irregular blue lines; irregular marks of pale blue on caudal fin.

Remarks
The length of the two specimens of longfin bannerfish, H. acuminatus obtained in this study is below the range of the size reported for this species (200 mm TL) (Randall, 1995).
There is no consensus concerning the presence of this species in the waters of the Arabian Gulf.Fischer & Bianchi (1984) reported the presence of this species in the fishing area number 51, Western Indian Ocean, but the name of the country was not given.Carpenter et al. (1997) mentioned its presence on the western coasts of the Arabian Gulf waters but did not state the country in which it was obtained.Steene (1978) also found the species in Arabian Gulf waters, but no specific mention was given to Iraqi waters.The present record confirms its presence in Iraqi waters.
Pomacanthus maculosus, as in the case of H. acuminatus, has been reported by Fischer & Bianchi (1984) to be present in the Arabian Gulf area in general and by Carpenter et al. (1997) to be present in the western coasts of the Arabian Gulf, but the name of the country is not given.Allen (1985) reported its presence in the waters of Bahrain, Saudi Arabia, and Qatar.Randall (1995) stated that this species is unusually abundant in the Arabian Gulf and Sea of Oman.This species is mentioned in the IUCN Red List as native to the Iraqi marine waters (Pyle et al., 2010), but this information has not been scientifically published.The present study confirms its presence in Iraqi marine waters.
The present record of H. acuminatus and P. maculosus is the result of extensive ichthyological collections and represents confirmation of these two genera in Iraqi waters.
Lack of previous records of H. acuminatus and P. maculosus from the Iraqi marine waters might be due to two possibilities: (i) lack of sampling in the area preventing the regular detection of these species that had been overlooked in the past; and (ii) specimens of fish species dealt with in the present study might originate from the ballast water as the Iraqi marine waters are very busy with oil tankers and commercial vessels.