INTRODUCTION
The Ampithoidae are herbivorous amphipods that are vital to the food chain in marine habitats (Grosse et al., Reference Grosse, Pauley and Moran1986; Klumpp et al., Reference Klumpp, Salita-Espinosa and Fortes1992). Tube building behaviour and silk production are also some interesting features of the ampithoids that have been studied by various authors (e.g. Appadoo & Myers, Reference Appadoo and Myers2003).
The genus Ampithoe Leach, Reference Leach1814 is the most speciose genus in the family Ampithoidae with more than 86 species listed in WORMS (Horton et al., Reference Horton, Lowry, De Broyer, Bellan-Santini, Coleman, Daneliya, Dauvin, Fiser, Gasca, Grabowski, Guerra-García, Hendrycks, Holsinger, Hughes, Jaume, Jazdzewski, Just, Kamaltynov, Kim, King, Krapp-Schickel, LeCroy, Lörz, Senna, Serejo, Sket, Tandberg, Thomas, Thurston, Vader, Väinölä, Vonk, White and Zeidler2016). Genus Ampithoe can be distinguished by the absence of the accessory flagellum in antenna 1, notched outer lobes of lower lip, and the spur on the peduncle of uropod 1 absent or reduced and rounded (Poore & Lowry, Reference Poore and Lowry1997).
Previous studies of the family Ampithoidae in the Persian Gulf has been limited to the reporting of two species of the genus Cymadusa from Kuwait (Jones, Reference Jones1986).
In the present study, a new species, Ampithoe qeshmensis, from Qeshm Island in the Persian Gulf is described.
MATERIALS AND METHODS
Materials were collected in April 2014 from the intertidal zone of Qeshm Island (26°43′58″N 55°50′2″E). The specimens examined were deposited in the Iranian National Institute for Oceanography and Atmospheric Science (INIOAC). The material was fixed in 70% ethanol, dissected in glycerol and then mounted by glycerin gelatin. Type material was drawn by Camera Lucida mounted on compound microscope. Due to the loss of mandible and first maxilla during dissection, these parts were drawn based on paratype.
SYSTEMATICS
Order Amphipoda Latreille, Reference Latreille1816
Family Ampithoidae Boeck, Reference Boeck1871
Genus Ampithoe Leach, Reference Leach1814
Ampithoe qeshmensis sp. nov.
(Figures1–4)
Fig. 1. Ampithoe qeshmensis sp. nov. (W♂) whole body, (U1♂) first uropod, (U2♂) second uropod, (U3♂) third uropod, (T) male telson from type specimen and (U1) first uropod of female paratype. Scale a: 0.1 and b: 1 mm.
Type material. Holotype male, 3.6 mm, INIOC1–37S, Qeshm Island, Persian Gulf, Iran (~26°30′N 55°48′E), seaweeds and associates, rocky intertidal zone, 21 April 2014, collected by Y. Layeghi. Paratype: 1 female, 4 mm, INIOC1–38S, same data as holotype.
Other material examined. Five females, four males and five juveniles, INIOC 1–39S, same data as types.
Type locality. Qeshm Island, Persian Gulf, Iran (~26°30′N 55°48′E).
DIAGNOSIS
(based on male) smooth body, antenna 2 densely setose and flagellum longer than peduncular article 5, mandibular palp article 3 longer than second one, palm of second male gnathopod slightly incised with short proximal thumb-like projection and robust seta, round and reduced distoventral spur on uropod 1.
DESCRIPTION
Based on holotype, male, 3.6 mm, INIOC1–37S.
Head. Head as long as deep (Figure 1). Antenna 1 (Figure 2) 1.4 × length antenna 2; peduncular article 1 subequal to article 2; flagellum not complete. Antenna 2 (Figure 2) peduncle densely setose on ventral margin; article 4 subequal to article 5; flagellum with 9 articles, 1.36 × length peduncular article 5. Upper lip (Figure 2) distally setose. Lower lip (Figure 2) outer plates notched forming a deep distal cleft. Mandible (holotype damaged, based on paratype) (Figure 2) molar well developed, triturating, accessory setal row with 4 serrate setae; palp 3-articulate, article 1 shorter than article 2; article 2 subequal in length to article 3, with 2 marginal palmate setae, article 3 with 6 terminal palmate setae. Maxilla 1 (holotype damaged, based on paratype) (Figure 2) inner plate with 2 setae; palp article 2 slender. Maxilla 2 (Figure 2) inner plate narrower than outer plate. Maxilliped (Figure 2) outer plate with row of large robust setae along medial margin, palp 4-articulate.
Fig. 2. Ampithoe qeshmensis sp. nov. (A1♂) first antenna, (A2♂) second antenna, (U.L♂) upper lip, (L.L♂) lower lip, (Mxp♂) maxilliped, (M2♂) second maxilla from type specimen and (A1♀) first antenna, (A2♀) second antenna, (Mx1♀) first maxilla, (Md♀) mandible from female paratype. Scale a: 0.1 and b: 0.5 mm.
Pereon. Gnathopod 1 (Figure 3) sexually dimorphic; smaller than gnathopod 2; coxa 1 smaller than coxa 2, produced, anterior margin straight, anteroventral corner rounded; basis longer than coxa, anterodistal lobe large, rounded, with 1 robust seta, 2 slender setae on posteroventral corner; ischium small, trapezoid-shaped; merus anterodistal lobe acute; carpus shorter than propodus, subtriangular, with slender setae on posterior margin, anterior margin with one robust seta; propodus subrectangular, length 2.14 × width, palm slightly acute, straight, with one defining large robust seta; dactylus subequal in length to palm, inner margin crenate. Gnathopod 2 (Figure 3) sexually dimorphic; coxa as long as deep; basis with large anterodistal lobe, with 3 slender setae on anterior margin, lobe with one robust seta; merus with long slender setae on ventral margin; carpus shorter than propodus, subtriangular, with small posterodistal lobe, lobe with long slender setae; propodus 1.6 × width, produced anterodistally, anterior margin with fringe of slender setae; palm acute, slightly incised, covered by long setae, posterodistal tooth short and apically blunt with defining one robust seta; dactylus subequal in length to palm, tapering evenly, inner margin crenulate. Pereopod 3–4 (Figure 4) basis slightly expanded, merus longer than carpus; propodus with 4 slender setae on posterior margin. Pereopod 5 (Figure 4) coxa without medial slender setae; basis expanded, with 4 short slender setae on anterior margin; merus short, subrectangular; carpus subquadrate, short; propodus subrectangular, slightly expanded distally, with 1 robust seta on posterior margin and 3 distal robust setae; dactylus strongly curved with inner smooth margin. Pereopod 6 (Figure 4) basis weakly expanded, with 4 short slender setae on anterior margin, posterior margin curved; propodus with 3 anterodistal robust setae. Pereopod 7 (Figure 4) similar to pereopod 6, propodus with 4 anterodistal robust setae.
Fig. 3. Ampithoe qeshmensis sp. nov. (G1♂) first gnathopod, (G2♂) second gnathopod from type specimen and (G1♀) first gnathopod, (G2♀) second gnathopod from female paratype. Scale 0.5 mm.
Fig. 4. Ampithoe qeshmensis sp. nov. (P3) third pereopod, (P4) fourth pereopod, (P5) fifth pereopod, (P6) sixth pereopod and (P7) seventh pereopod from type specimen. Scale 0.25 mm.
Pleon. Uropod 1 (Figure 1) sexually dimorphic; peduncle with 3 robust setae, with long fringe of slender setae, with small rounded distoventral spur; outer ramus without lateral robust setae; inner ramus with 2 lateral robust setae, each ramus with 4 terminal robust setae. Uropod 2 (Figure 1) peduncle with 2 dorsolateral robust setae; rami subequal in length; outer ramus with 2 lateral and 4 terminal robust setae; inner ramus with 3 lateral and 4 terminal robust setae. Uropod 3 (Figure 1) peduncle longer than broad; peduncle with 4 distal robust setae, inner ramus 0.4 × peduncle, with 4 apical robust setae and 4 long simple setae; outer ramus with 2 apical large curved robust setae; inner ramus with one robust and three long simple setae. Telson (Figure 1) subtrapezoidal, apically truncated, with 4 apical and 2 lateral setae.
Female (sexually dimorphic characters). Based on paratype, 4 mm, INIOC1–38S. Antenna 1 (Figure 2) flagellum 20-articulate. Antenna 2 (Figure 2) flagellum 12-articulate. Gnathopod 1 (Figure 3), subequal to gnathopod 2; anterodistal lobe of basis with 1 slender seta, carpus anterior margin without one robust seta. Gnathopod 2 (Figure 3) coxa as long as deep; basis without 3 slender setae on anterior margin, lobe without robust seta; palm sinusodial, with 1 robust seta defining palm. Uropod 1 peduncle with 10 lateral robust setae, with long fringe of slender setae, without small rounded distoventral spur; outer ramus with 5 lateral robust setae; inner ramus with 8 lateral robust setae.
Habitat. Living in intertidal zone, on macroalgae of genus Laurencia.
Etymology. This species is named for its type locality, Qeshm Island.
Remarks. Ampithoe qeshmensis sp. nov. is the first representative of the genus Ampithoe from Qeshm Island in the Persian Gulf. The new species is most similar to A. cookana Peart, Reference Peart2007; A. katae Peart, Reference Peart2007; A. kava Myers, Reference Myers1985; A. kuala Myers, Reference Myers1985; A. platycera Sivaprakasam, Reference Sivaprakasam1970; and A. ramondi Audouin, Reference Audouin1826.
Ampithoe qeshmensis differs from A. cookana, A. katae, A. kuala, A. platycera and A. ramondi by having a clearly rounded and reduced distoventral spur on the peduncle of the male uropod 1.
The main characters that separate the new species from Ampithoe kava are the ratio of the flagellum to the peduncular article 5 in Antenna 2 (about 1.4 × in A. qeshmensis, less than 1 × in A. kava), presence of a robust seta on the palm of gnathopod 2 in male (absent in A. kava) and the palm structure in gnathopod 2 (thumb-like with narrow cleft in A. kava, but short thumb-like without cleft in A. qeshmensis).
Ampithoe qeshmensis resembles A. cookana and A. katae based on the propodus of second gnathopod (short thumb-like defining palm) while it differs with A. cookana in the carpal robust setae of gnathopod 2 (more than 4 in A. cookana, absent in A. qeshmensis), a robust seta on the palm of second gnathopod and on the basal lobe of the first gnathopod in A. qeshmensis. It is different from A. katae based on the shorter second mandibular palp article than ultimate article (0.82 ×) in A. qeshmensis, while it is longer in A. katae (1.35 ×), and also the defining robust setae on the palm of gnathopod 2 in A. qeshmensis.
Recently Ampithoe ramondi was recorded from Kuwait in the north-west of the Persian Gulf (Myers & Nithyanandan, Reference Myers and Nithyanandan2016). The type locality of A. qeshmensis is on the eastern part of the region. Consequently, the family Ampithoidae has four members in the Persian Gulf including: Cymadusa filosa (Jones, Reference Jones1986; Myers & Nithyanandan, Reference Myers and Nithyanandan2016), C. setosa (Jones, Reference Jones1986), A. ramondi (Myers & Nithyanandan, Reference Myers and Nithyanandan2016) and A. qeshmensis.
ACKNOWLEDGEMENTS
The authors would like to thank Dr Abdolvahab Maghsoudlou and Vahid Sepahvand for collaboration during this study.
FINANCIAL SUPPORT
This study was financed by the Iranian National Institute for Oceanography and Atmospheric Science (INIOAS) (project grant number ‘392-011-11').
