Checklist of cnidarians from Pakistani waters

We present a species list of the marine cnidarians recorded from the Pakistani waters, northern Arabian Sea. It comprises a total of 119 species distributed in 41 families, 14 orders and 4 classes. With 44 species, the order Scleractinia (class Anthozoa) is the best-represented cnidarian taxon. Cnidarians from Pakistan are a poorly studied group which is mentioned in few occasional papers; no new species have been described from the region. The present paper will provide baseline information for future studies in Pakistan.


INTRODUCTION
Members of the phylum Cnidaria comprise a diverse group of invertebrates which all have a common and unique feature, the presence of cnidae (Marques and Collins 2004).The number of species listed for the phylum varies among different authors, Zhang (2011), for example, gives 10,105 species.Cnidarians are an important taxonomic group of study; they can be found in all habitats from the intertidal to the deep-sea and from the tropics to the poles.In many habitats they even dominate the benthic communities.Many species are ecologically important predators or prey, others are known for their capacity of hurting humans, some produce important economic losses, others are target species for bioprospecting.As basic metazoans, cnidarians are important for understanding evolutionary patterns.
The marine invertebrate fauna from the coast of Pakistan is poorly known (Kazmi and Naushaba 2013) and even less is known on cnidarian biodiversity with only a few papers published about the group (Table 1).Here we have made an attempt to present an updated checklist of cnidarians from Pakistani waters, northern Arabian Sea.

MATERIALS AND METHODS
The species list was compiled through an extensive literature search.The marine cnidarians listed here were based upon published records from the coast of Pakistan and its off coastal waters of the northern Arabian Sea; the first record come from 1937.The status of all listed species was confirmed using established databases (AIMS Coral Fact Sheets, Schuchert 2014, WoRMS).The classification used here followed Daly et al. (2007).The collection points mentioned in the literature were shown by numbers (71)(72)(73)(74)(75)(76)(77)(78)(79)(80)(81)(82)(83)(84)(85) in Figure 1, and mentioned along with the localities in Table 1.Collection points 28-66 represent GPS positions of Siphonophorae (Ali-Khan & Shehnaz 2001b: 28, table 1).Abbreviations are NSS (Northern Sheltered Side), RS (Roadrigues Shoals), and TFR (Triple Fin Rocks).For some species, no specific locality or GPS position along Karachi coast of Pakistan mentioned (Haque 1977;Stiasny 1937); this is indicated in the table by a question mark.Locality, Pasha Bundar (Moazzam and Moazzam 2006), could not be identified and was therefore not shown in the map.
Because there were no voucher specimens, it was not possible to check if the identifications are correct.However, a few doubtful records were pointed out and were mentioned in the table by using a question mark in front of the author citation in the references column.The occurrence in the Indian Ocean of most of the hydroids listed here were confirmed by Mammen (1963Mammen ( , 1965aMammen ( , 1965b)); the siphonophores by Rengarajan (1973Rengarajan ( , 1974Rengarajan ( , 1975Rengarajan ( , 1983) ) and Daniel (1985).

RESULTS
Table 1 provides the compiled data on the cnidarian species recorded from Pakistani coast and its off coastal waters.The numbers of species per higher taxa reported for Pakistan are: 62 Anthozoa (4 Actiniaria, 1 Antipatharia, 1 Ceriantharia, 11 Octocorallia, 44 Scleractinia, 1 The reason why cnidarians are so little known in Pakistani waters is probably related to the absence of specialists in the area.The decline of taxonomists is a phenomenon that can be observed worldwide (Disney 1998;Godfray 2002).In addition, identification especially of the soft-bodied hexacorals (Häussermann 2004) and of octocorals needs years of experience and is done by fewer and fewer scientists.We propose to promote the formation of taxonomic specialists who go in the field to collect cnidarians and later identify them, and to increase funding for this type of baseline research to improve the knowledge about the phylum Cnidaria in Pakistan.The species list compiled for the present paper is supposed to be the pillars of further research on cnidarians in the region.

Remarks on recorded species
The various species of hydrozoans, octocorals and anemones reported by Haque (1977) are briefly described and without figures.Voucher specimens are not available, and thus, confirmation of identifications and further comments are complicated.

DISCUSSION
Cnidarian research along the coast of Pakistan has received little attention, which is reflected by the few papers published on the topic (Table 1).The John Murray Expedition in 1933-34 travelled through most of the western part of the Indian Ocean (Sewell 1935;Morcos 2004) and only just two records (Pelagia noctiluca, Cephea sp.) came from Pakistani waters, off Karachi.The next paper dealing with cnidarians (hydrozoans, octocorals and anemones) from the Pakistani coast appeared is that of Haque (1977).Since then a few other papers appeared on different cnidarian groups: siphonophores (Ali-Khan andShehnaz 2001a, 2001b); hydroids (Moazzam and Moazzam 2006;Gul and Gravili 2014); cubo-and scyphomedusae (Tahera and Kazmi 2006;Kazmi and Sultana 2008;Muhammed and Sultana 2008;Gul and Morandini 2013;Gul et al. 2014); corals (Siddiqui et al. 2011;Ali et al. 2014); zoanthids (Gul 2013); and hydromedusae (Gul and Gravili 2013).All of them, however, only contain new records and no new species.The occurrence of corals along Pakistani coast just was pointed out relatively recently (Kazmi and Kazmi 1998;Ishaq et al. 2003;Wilkinson 2004); but Siddiqui et al. membranaceus, is indeed not an Indian Ocean species but restricted to the Mediterranean Sea (S.N.Stampar, personal communication); Plumularia insignis is also not an Indian Ocean species (T.P. Miranda, personal communication; see also Genzano 1995: 6;Vervoort and Watson 2003: 396); they were mentioned by Haque (1977) and here considered because of these previous records.The same is true for the cubozoan jellyfish Carybdea marsupialis recorded from Pakistan (Kazmi and Sultana 2008); however, the figures provided in the paper suggest erroneous identification.This species is in fact restricted to Mediterranean Sea (I.Straehler-Pohl, personal communication).Similarly, Gul and Morandini (2015) argued that the Rhizostoma pulmo record (Muhammed and Sultana 2008) is also based upon erroneous identification; there is no access to the specimens, but the figures indicate that the specimens actually belong to a different genus.
Although the order Scleractinia appeared in the list as the best-represented taxon, many are either doubtful or not fully identified.The same is true for the alcyonacean species.We conclude that the taxonomic study of Pakistani soft and hard corals needs a detailed approach and attention.
For several of the described taxa we would have expected a much larger diversity; more specific sampling techniques and detailed observations will certainly provide more records in the future.  1 showing the precise site of collection of the species.For abbreviations see text.Question marks in front of reference means that we consider the record doubtful probably misidentified and, those in front of the locations (Karachi, off Karachi) mean no specific locality or GPS position not mentioned.
. | Cnidarians from Pakistani waters (2011) were the first to give species names.A recent paper on the subject (Ali et al. 2014) mentioned that the distribution and growth of corals is poor in Pakistan.

Figure 1 .
Figure 1.Map showing collection points (red dots, 1-68, 71-85) along the coast of Pakistan and its off coastal waters, the northern Arabian Sea.Coastline of Pakistan comprises of Sindh and Baluchistan provinces.From point 4 (right) to point 9 and 72 (left) is the coastal area of Karachi city at Sindh.

Table 1 .
Checklist of cnidarians from Pakistan and off its coastal waters.Numbers after each collection point correspond to the numbers in Figure
Continued Gul et al. | Cnidarians from Pakistani waters