Monoliropus kazemii, Momtazi, Farzaneh & Sari, Alireza, 2013

Momtazi, Farzaneh & Sari, Alireza, 2013, Intertidal caprellids (Crustacea: Amphipoda) of the Persian Gulf and the Gulf of Oman, with description of three new species, Zootaxa 3717 (2), pp. 195-223 : 204-210

Monoliropus kazemii sp. nov.

( Figs 6–10 )

Material examined. ZUTC Amph. 2407, seven males and one female, Loc 3 (Nakhl-Nakhoda, 27°11'21"N, 56°21'32.7"E), December 2010; ZUTC Amph. 2408, two males, 20 females, Loc 5 (Bostano, 27°04'41"N, 56°00'01"E), March 2011; ZUTC Amph. 2410, four females, Loc 18 (Nayband, 27°23'52"N, 52°39'21"E), October 2009; ZUTC Amph. 2411, two males, three females, Loc 26 (Chapahn, 28°20'53"N, 51°11'E), March 2011.

Description. Holotype ♂. (ZUTC Amph. 2421, Nakhle-Nakhoda, 27°11'21"N, 56°21'32"E). Total length, 8.52 mm.

Lateral view ( Fig. 6 and Fig. 10 A). Male body length 8.52 mm; Head, 0.5 mm, smooth. Pereonite 1 fused to head, 0.78 mm, suture present. Pereonite 2, 1.21 mm, with tubercles anteriorly. Pereonite 3, 1.5mm, with anterior tubercle. Pereonite 4, 1.65 mm, with tubercule anteriorly. Pereonite 5, 1.85 mm largest. Pereonite 6, 0.66 mm. Pereonite 7, 0.37 mm.

Gills ( Fig. 6 ), on pereonite 3 and 4. Gill 4, length 0.35× pereopod 4, elongate. Gill 3 length 0.21× pereopod 3, elongate.

Mouthparts ( Fig. 7 and Fig. 10 F): Upper lip ( Fig. 7 UL), symmetrically bilobed, with multi set of setae arranged as rows. Lower lip ( Fig. 7 LL) with well demarcated inner lobes; inner and outer lobes with setules. Left Mandible ( Fig. 7 LMd), incisor with 5 teeth and lacinia mobilis with 5 teeth and 3 accessory setae; molar well developed; palp 3-articulate; article 2 with 7 setae; setal third article of mandibular palp with two unequal distal seta, and two unequal medial setae and an antero-distal projection. Right Mandible ( Fig. 7 RMd), incisor with 5 teeth followed by numerous tooted plates and 2 accessory setae; molar well developed; palp 3-articulated; article 2 with 6 simple setae; third article of mandibular palp with two unequal distal setae, and two unequal medial setae, one submedial setae, and with a distal projection. Maxilla 1 ( Fig. 7 Mx1), inner lobe with seven stout apical setalteeth setae; palp distal article with four apical robust setae, one subapical seta and four simple medial setae. Maxilla 2 ( Fig. 7 Mx2), inner lobe with seven apical and one subapical seta, outer plate with 10 apical setae. Maxilliped ( Fig. 7 Mxp), inner plate subquadrate, not reach to first article of palp, with 4 teeth and some simple and plumose setae, outer plate much larger, with one seta in apical notch, followed by a rounded, slightly bifid lobe and a strong medial notch with 2 setae and 8 superficial setae; palp 4-articulated, first with 1 seta, second article with 12 setae, third article with antero-distal projection and 12 setae, last article minutely serrated in grasping margin and with 3 setae.

Antennae ( Fig 6 ). Antenna 1 ( Fig. 6 A1), shorter than half of body length, first and third article of peduncle subequal; second ones largest, 1.7× first segment, flagellum 11-articulated, shorter than peduncle. Antennae 2 ( Fig. 6 A2), longer than peduncle of first antenna, flagellum bi-articulate, second antenna with some small simple and no swimming setae.

Gnathopods ( Fig. 6 ). Gnathopod 1 ( Fig. 6 Gn1), basis equal to propodus length; ischium with two posterior setae; merus and carpus fused; propodus subelliptical with some superficial setae; palm entire, bearing one proximal grasping spine followed with some robust and simple setae; dactylus serrated and bear some fine setae, reach to end of propodus. Gnathopod 2 ( Fig. 6 Gn2 and Fig. 10 , B), inserted in middle of pereonite 2; basis longer than propodus; ischium semiquadrate; merus round; carpus short and triangular; propodus oval, palm straight with proximal projection carrying one robust seta, a medial sharp and distal triangle round projections present; dactylus strongly arched and serrated with simple short setae and peg-like seta.

Pereopods ( Fig. 8 ). Pereopod 3 ( Fig. 8 P3), slender, 1-articulate with 3 apical setae and 1 subapical seta. Pereopod 4 ( Fig. 8 P4), slender, 1-articulate with 3 apical setae and one subapical seta. Pereopod 5 ( Fig. 8 P5), hexa-articulated, less robust than pereopods 6 and 7; carpus with one robust and 11 fine setae, propodus with strong grasping spine on small projection followed with some setae on palm. Pereopods 6 and 7 ( Fig. 8 P6-7) similar in shape but pereopod 7 larger than pereopod 6; propodus with a pair of grasping spines on a small projection, then notched followed by two small projections and two curved robust setae.

Abdomen ( Fig. 7 Ab and Fig. 10 C, D, and E). A pair of 2-articulated appendages, first article with three lateral setae, ultimate appendage constricted halfway along their length and with tuft and two long apical setae on distal part and three medial setae. Penes lateral. Dorsal lobe with two plumose setae.

Allotype ♀. (ZUTC Amph. 2422, Nakhle-Nakhoda, 27°11'21.0"N, 56°21'32"E). Total length, 4.4 mm.

Lateral view ( Fig. 9 ). Body length 4.4 mm. Body ornamentation as same as male. Antennae ( Fig. 9 A1–2) similar to male. Gnathopod 1 ( Fig. 9 Gn1) without sexual dimorphism. Gnathopod 2 ( Fig. 9 Gn2) inserted on anterior half of pereonite 2, palm straight with proximal projection carrying one robust seta, medial sharp projection rudimentary. Oostegite of pereonite 3 setose ( Fig. 9 Os1) and naked in pereonite 4 ( Fig. 9 Os2). Abdomen ( Fig. 9 Ab), with a dorsal and two lateral lobes. Each lateral lobe with two setae and dorsal lobe with two plumose setae.

Remarks. Monoliropus kazemii is the only member of genus Monoliropus in the Persian Gulf. Arimoto (1976) described the genus Monoliropus based on discriminative characters including: “bi-articulate flagellum of antenna 2; mono-articulate pereopods 3 and 4; 6-articulate pereopod 5; male abdomen with a pair of bi-articulate appendages and a pair of lobes; female abdomen with a pair of lobes”.

The genus Monoliropus has six species that include; M. enodis Rayol & Serejo, 2003 , M. agilis Mayer, 1903 ; M. concavimanus Horton, 2008 , M. falcimanus Mayer, 1904 , M. hapipandi Guerra-García, 2004 b, and M. tener Arimoto, 1976 .

Monoliropus kazemii is specified by bi-articulate abdominal appendage, straight male second gnathopod and setal formula with two apical and two medial setae. Abdominal appendage in this species is composed of a basic article and followed by an article that decreased in width toward distal end.

The main diagnostic characters between M. kazemii and other species of genus Monoliropus is presented in Table 3. In M. macoranicus the setal formula is specified within Monoliropus species and not having a 1+X+Y+1 pattern. Previously, the setal formula was considered by Arimoto (1976) as a distinctive character at species level in genus Monoliropus . The male second gnathopod in four species of Monoliropus were straight including; M. agilis , M. enodis , M. hapipandi and M. kazemii . Although the body ornamentation is smooth in M. enodis and M. agilis but there are lateral tubercles in pereonites 2 – 4 in M. kazemii . The abdominal appendage in M. hapipandi is the main diagnostic character between M. kazemii and M. hapipandi .

Monoliropus kazemii is morphologically more close to M. falcimanus . In the description of M. falcimanus Mayer, 1904 from Ceylon, characters were not fully treated. There is another short description of this species from the Indian Ocean by Sivaprakasam (1977). Other studies of M. falcimanus were restricted to its record from south Arabian Sea (Barnard 1937) and the Philippines (Laubitz 1991). The abdominal appendages were different in these descriptions. Mayer (1904) stated 1-articulated abdominal appendage, while Laubitz’ (1991) illustration shows one pair of 1-articulated appendages with a constriction in the middle. Sivaprakasam (1977) described it as biarticulate appendages without decrease in width. Despite differences in the abdominal appendage, all reported materials of M. falcimanus have the same setal formula and concave propodus. The new species of the Persian Gulf is distinguished by a species seta arrangement in the third article of mandibular palp and a straight propodus shape in juvenile and completely mature individuals.

Distribution. In the present study, M. kazemii is the only caprellid that was collected from the center of the Persian Gulf (Loc 26, Chapahn; and Loc 18, Nayband).

Figures

FIGURE 6. Monoliropus kazmii sp. nov. 8.52 mm. Holotype ZUTC Amph. 2421, Nakhl-Nakhoda. Scale a = 1 mm and b = 0.5 mm.

FIGURE 7. Monoliropus kazmii sp. nov. 8.52 mm. Holotype ZUTC Amph. 2421, Nakhl-Nakhoda. Scale a = 0.1 mm and b = 0.02 mm.

FIGURE 8. Monoliropus kazmii sp. nov. 8.52 mm. Holotype ZUTC Amph. 2421, Nakhl-Nakhoda. Scale a = 0.5 mm and b = 0.02 mm.

FIGURE 9. Monoliropus kazmii sp. nov. 4.4 mm. Allotype ZUTC Amph. 2422 (female), Nakhl-Nakhoda. Scale a = 0.5 mm and b = 0.1 mm.

FIGURE 10. Monoliropus kazmii sp. nov. Paratype ZUTC Amph. 2425 (male), Nakhl-Nakhoda. A: dorsal view, B: second male gnathopod, C: ventral view of abdomen, D: lateral view of abdomen, E: abdomen appendage, F: mouthparts. Scale a = 0.1 mm and b = 0.02 mm.