EurAsian Journal of BioSciences Eurasia J Biosci 14, 5193-5196 (2020) New record species of genus Acartia; Dana, 1846 (Crustacean: Copepod: Calanoida) from Iraq Hajer Mohammad 1, Hanan Zwair 1* 1 Department of Biology, College of Education for Pure Science, University of Karbala, IRAQ *Corresponding author: [email protected] Abstract The present study provides a new record species Acartia discaudata (Giesbrecht, 1882). Samples were collected from Shat Al -Kofa in the Al -Najaf AL- Ashraf province –Iraq at september.2019.External morphological characters were used to describe and identify species under study. Such characters are: Prosoma 5- segment. Urosoma 4-segment, genetal double segment elongated, ventral side with one stout and long spine. caudal rami short, both rami with 5 plumous seta. Antennules 18-segments. Antenna, Exp 7-segment. P1-P2: Enp 2- segments, exp 3- segments P3-P4 both 3- segments. P5, Exp with one stout spine and one seta. Keywords: Copepoda, Calanoida, taxonomy, Acartia, Dana, 1846, Iraq Mohammad H, Zwair H (2020) New record species of genus Acartia; Dana, 1846 (Crustacean: Copepod: Calanoida) from Iraq. Eurasia J Biosci 14: 5193-5196. © 2020 Mohammad and Zwair This is an open-access article distributed under the terms of the Creative Commons Attribution License. INTRODUCTION MATERIALS AND METHODS Calanoid is very successful organisms in marine, hard and salt environments as well as freshwater Twenty two samples were collected by plankton net (Bradford-Grieve et al,2010).Order Calanoida included (35mm) from Shat Al -Kofa in the Al -Najaf AL- Ashraf 42 families and 289 genera, of which only 4 families province –Iraq at September.2019 “ SN 32̊ 02 6.6157” “ existed exclusively in the aquatic environment and 22 WE 44̊ 24 53.5033”.Samples were preserved in vials families in the freshwater and marine environment containing 70 % Ethanol with 20% glycerin and fixed by (Dussart and Defaye,2001; 2002; Boxshall and Halsey, using lactic acid With the addition dye Bengal Rose. 2004). Hence, the species that fall under this order are Dissection was done using dissection needles. Prosoma characterized by a high ability to successfully survive in and urosoma and the other appendages were separated fresh, brackish and salt aquatic environments (Bradford- respectively. All parts illustrated by using microscope Grieve et al, 2010). The members of order Calanoida live with aid a camera Lucida. Taxonomic keys:(Park, 1995; in fresh water at 25% and in salt 75%, and some marine Sandercock and Scudder 1994; Mauchline, 1998; Bilton, species are benthic and others are plankton (Mauchline, 2001; Figueroa,2011; Phan et al, 2015; Bledzki and 1998). The distribution of zooplankton is influenced by Rybak, 2016) used for identification of specimens general water conditions, monsoons and currents (Wang et al, 2019). RESULTS AND DISCUSSION Female Acartia excreta eggs freely in the water. Systematic When the eggs hatch, the Nauplii undergo 6 distinct Phylum: Arthropoda latreille, 1829 stages until they become a copepodites, then they Class: Crustacea Brunnich, 1772 undergo 6 more stages until they reach full adult Order: Calanoida; Sars, 1903 copepoda. (Marcus and Wilcox 2007). Some species of Family: Acartiidae; Sars, 1903 Acartia go through a dormant stage, which is part of their genus: Acartia; Dana, 1846 life cycle. It produces resting eggs when conditions are species: Acartia discaudata (Giesbrecht, 1882). not suitable for the growth and development of Nauplii Diagnosis: Body (Fig 1): Total length (1.24 mm), (Miller,2004).Acartia feeds mainly on phytoplankton and Prosoma oval, consist of 5 -segments. Eye single and is known as a consumer of their own eggs and nauplii, middle. Antennules extends cephalothorax and reaches ciliates and rotifers(Marcus and Wilcox 2007). Acartia is known as the vertical migration pattern, as it swims to the depths during the day and rises to the surface during Received: April 2019 the night (Durbin,1990). Accepted: March 2020 Printed: October 2020 5193 EurAsian Journal of BioSciences 14: 5193-5196 (2020) Mohammad and Zwair Fig. 1. Acartia discaudata (Giesbrecht, 1882), A: Adult female, lateral view Fig. 3. Acartia discaudata (Giesbrecht, 1882). B: Mandible C: Maxillule D: Maxilla Maxillule (Fig 3): Consist of Coxa and Coxal epipodite with 4 plumose setae. Exp: with 3 plumose seta. Enp: with 2 plumose seta. Maxilla (Fig 3): Uniramous, consist of pre- coxa, Fig. 2. Acartia discaudata (Giesbrecht, 1882). A: coxal epipodite with 3 plumose seta. coxa connected Antennules B:Antennae with tow coxal endites each segment with one plumose seta. Basal endites with one plumose seta. Enp: consist the end of the caudal rami. Urosoma slender, consist of of two segment, second segment with 3 plumose seta. 4- segments. Genital Double segment with ventral large Maxilliped (Fig 4): Uniramous, coxa large and spine. caudal rami short and wide each branch with 5 irregular, Bases small segment. Enp: consist of 3 short plumose seta equal in length. segment,first segment with 3 plumose seta, second Antennules (Fig 2A): long and slender consist of 18- segment small. third segment with 3 plumose seta. segments different in shape and size. 1(1Se), 2 (0), 3 (1Se), 4 (1Se +1Sp), 5 (0), 6 (1Sp),7 (1Se +1Sp), 8 (1Se), 9 (1Se), 10 (0), 11 (0), 12 (1Se), 13 (1Se), 14 (0), 15 (0), 16 (1Se), 17 (1Se), 18 (2 Se). Antennae (Fig 2B): Basal segment irregular in shape, Exp: consist of 7 small segment, seventh segment with tow plumose seta equal in length.Enp: consist of 3 large and elongate segment, third segment with 5 plumose seta equal in length. Mandible (Fig 3): Basal segment irregular in shape Exp: consist of 3 -segments, first segment with number of hairs, second segment with one long plumose seta. third segment with 4 plumose seta, three of them terminal.Enp: 3-segment,first with 3 setae,third with 3 terminal setae. 5194 EurAsian Journal of BioSciences 14: 5193-5196 (2020) Mohammad and Zwair Fig. 4. Acartia discaudata (Giesbrecht, 1882). A:Maxilliped B: Pereopod 1 C: Pereopod 2 Fig. 5. Acartia discaudata (Giesbrecht, 1882). A Pereopod 3 B: Pereopod 4: C: Pereopod 5 Table 1. Pereopod (P1) and (P2) : Enp : 2 segment , Exp : 3 segment (P3) and (P4) : Enp and Exp 3 segment . Seta / Spine armature of P1-P4 segment with one seta and one stout spine. End: one Swimming Legs Coxa Basis Exp Enp spine. P1 0-0 0-0 0-1; 0-1; 4-1 0-0 ; 4-0 P2 0-0 0-0 0-0 ; 0-0 ; 4-0 0-0 ; 4-0 P3 0-0 0-0 0-0 ; 0-1 ; 5-0 1-0 ; 2-0 ; 2-0 CONCLUSION P4 0-0 0-0 1-0 ; 1-1 ; 3-0 0-0 ; 0-0 ; 4-0 Genus Acartia is rare in the central regions. Species Acartia discaudata is characterized:Urosoma slender, Swimming legs (Fig 4, 5): consist of 4- segments. Genital Double segment with Pereopod (P1) and (P2): Enp: 2 segment, Exp: 3 ventral large spine. caudal rami short and wide each segment (P3) and (P4): Enp and Exp 3 segment. Seta / branch with 5 short plumose seta equal in length.A1:18 Spine armature of P1-P4 as in Table 1. segment, A2: Exp: consist of 7 small segment. P 5 Exp: Pereopod 5 (Fig 5.): Coxa width is more than length, consist of 2 -segment, second segment with one seta Basis irregular, Exp: consist of 2 -segment, second and one stout spine. End: one spine. REFERENCES Bledzki L A and Rybak J I (2016)Freshwater Crustacean Zooplankton of Europe: Cladocera & Copepoda (Calanoida, Cyclopoida) Key to species identification, with notes on ecology, distribution, methods and introduction to data analysis. 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