First record of peregrine shrimp Metapenaeus stebbingi Nobili, 1904 (Crustacea, Decapoda: Penaeidae) in the Iraqi waters, North-West Arabian Gulf

: One male specimen of the species Metapenaeus stebbingi Nobili, 1904 was first recorded in November 2021 from the Iraqi territorial waters, Northwest of the Arabian Gulf. Therefore, the investigated shrimp species nominally corresponds to the original description of M. stebbing through the main diagnostic features. It must be adopted in the spread and expansion of species, a new record of the area, and a distinctive addition to the species of commercial shrimp within the Iraqi marine waters.


Introduction:
The family Penaeidae is the largest of the crustaceans representing the most abundant species of commercial importance. Shrimp in comparison with arthropods, are characterized by large size most common as seafood 1,2 . Shrimp of two the genus Penaeus and Metapenaeus, are major commodities in the fisheries sector 2 . The genus Metapenaeus is one of the important shrimp genera that is widespread throughout the Indo-Pacific regions, represented by ten species, including Metapenaeus stebbingi, out of worldwide 24 species 3 . The shrimp was studied in Kuwaiti waters, and four species of commercial shrimp were recorded, they were divided into two groups, the first living in muddy bottoms under the tidal, and included Penaeus semisulcatus, Parapenaiopsis stylifera, and M. stebbingi, while the second group included Metapenaeus affinis in the region Tides 4 . Some studies have shown that M. stebbingi makes up 4% or less of the total shrimp catch in the Arabian Gulf waters, as is the case in Kuwaiti waters, where most of the catch is P. semisulcatus (40%) and M. affinis (48%). as well as in Iranian waters where most of the shrimp catch is from Penaeus merguiensis (60-70%) 5,6 .
The genus Metapenaeus in the Iraqi is represented by the one species M. affinis, first recorded by 7 . Recently, a campaign has been organized to classify some of the invertebrates of the Iraqi coast, including the shrimp log, Alpheus edwarsi 8 . The most important species of commercial shrimp in the Iraqi regional and internal waters are P. semisulcatus, M. affinis, P. stylifera and Macrbrachium nipponense, which can be used in aquaculture 9,10 . Despite the scientific development that took place using molecular classification to classify aquatic invertebrates, the phenotypic characteristics remained the most important factor in classifying and diagnosing their species 11,12,13 . It is possible to depend on this species of commercial shrimp that can be exploited in farming. The current study aims to report the first record of shrimp M. stebbingi in the Iraqi marine waters, Northwest of the Arabian Gulf as a new record of commercial shrimp in the Iraqi marine catch.

Materials and methods:
One live male M. stebbingi shrimp was collected in November 2021 from the current study area (29° 51 '18° N 48° 40' 52° E) NW of the Arabian Gulf (

Description
The shrimp has a body almost devoid of whiskers. It is characterized by creamy yellow color with gray spots and rust on the body and pereiopods. The antennas and the distal part of uropods are grayishpurple rust. Rostrum is characterized by seven teeth on the dorsal margin, however no teeth were found on the ventral margin. The posterior epigastric segmentʼs dorsal tooth is well separated from the other rostral teeth. All specifications (spots and teeth) are indicated in Fig. 2 A and B. Post-spine keel is low, wide, and ends near the middle of the carapace length, this, the latter is supplied with antennae and spines of the liver.  The merus of the fifth pair of pereiopods has a close degree followed by a compressed rounded tuber (Fig. 4 A and B). Telson has a median groove, characterized by being lined with small cracks in the horizontal edges (Fig. 5). The body is naked, with some hairs. The rostrum is straight, slender, and narrow, extending forward until the outer end of the peduncle of the horn or beyond that. The rostrum contains between seven to ten dorsal teeth with no teeth on the ventral edge. There is a dorsal back spine above the stomach area. The complaint is separate from the rest of the rostrum thorns and compared to P. semisulcatus which is distinguished by teeth found on both sides of the dorsal and ventral rostrum 15,17 . The carapace area contains two spines (cornea and hepatic) with a distinct gill crest but without longitudinal sutures. There is a groove behind the snout, low and wide, ending near the middle of the length of the shield.
The telson contains a medial groove whose lateral edges are armed with fine spicules. The branching segment of the fifth pair of pereiopods (walking legs) contains a foramen followed by a compressed and rounded tubercle.
The male organ contains a pair of median processions, each with a typical, forward-facing, serrated appendix on the ventral margin, and there are two longitudinal appendages next to each other in the median part of this organ. However, the female organ in the females has a transverse crest protruding forward between the two lateral plates, and these lateral plates are triangular. Individuals are white-yellowish with scaly gray and red spots. It has a total length of 13.9 cm and is common between 8-12 cm. It lives on sandy clay soil at a depth of between 50-90 meters, and this is the depth at which it is generally found 4,18 . Fished by pocketshaped nets, consume fresh 18 .

Remarks
Only one species of the genus Metapenaeus Wood-Mason and Alcock, 1891 was known in the Iraqi coast overlooking the Arabian Gulf. The M. affinis 17 , and the M. stebbingi can be easy to distinguish and isolate from the M. affinis through its smaller size, color, and shape of the male member's petasma, as well as from the shape of the thigh with merus 5 th pereiopod. The record of M. stebbingi is the first on the marine Iraqi territorial waters northwest the Arabian Gulf. It is possible to rely on the taxonomic key mentioned by 19 to distinguish between M. affinis and the species recorded (M. stebbingi) in the present study.