Neocallichirus darvishi, Sepahvand & Komai & Momtazi & Shahabi, 2018

Sepahvand, Vahid, Komai, Tomoyuki, Momtazi, Farzaneh & Shahabi, Saeed, 2018, A new species of the ghost shrimp genus Neocallichirus Sakai, 1988 from Iran, and new record of N. manningi Kazmi & Kazmi, 1992 (Decapoda: Axiidea: Callianassidae), Zootaxa 4527 (2), pp. 239-254 : 241-246

publication ID	https://doi.org/ 10.11646/zootaxa.4527.2.5
publication LSID	lsid:zoobank.org:pub:7511F0C5-E7B9-458A-BD1B-2E485ED820A9
DOI	https://doi.org/10.5281/zenodo.5958060
persistent identifier	https://treatment.plazi.org/id/3DDC9AA7-D86A-45DD-8F06-B106C7294233
taxon LSID	lsid:zoobank.org:act:3DDC9AA7-D86A-45DD-8F06-B106C7294233
treatment provided by	Plazi
scientific name	Neocallichirus darvishi
status	sp. nov.

Treatment

Neocallichirus darvishi n. sp.

( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Material examined. Holotype: male (cl 8.2 mm, tl 34.5 mm), INIOC-1-99S, DNA voucher, Persian Gulf , Oli Village, 27°50′14.62″N, 51°53′24.85″E, Jan. 2015, sandy-muddy substrate with boulder, coll. V. Sepahvand. GoogleMaps

Allotype: female (cl 6.7 mm, tl 26.2 mm), INIOC-1-100S, same data as holotype.

Paratype: 1 ovigerous female (cl 9.1 mm, tl 36.2 mm), INIOC-2-9S, DNA voucher, Gulf of Oman, Tis, 25°21′25″N, 60°83′17″E, Apr. 2015, coll. V. Sepahvand.

Description. Carapace ( Fig.1A, 1C, D View FIGURE 1 ) subequal in length to pleomeres 1–3 combined; frontal margin ( Figs.1A, B View FIGURE 1 ) with triangular, sharply pointed rostrum reaching approximately half length of eyestalks, curving downward; no conspicuous projections lateral to rostrum. Linea thalassinica distinct, extending to posterolateral margin of carapace; dorsal oval clearly demarcated with deep cervical groove and shallow anterior and transverse grooves behind rostral base; anterolateral projection subtriangular, bluntly pointed; anterolateral sinus deep, Ushaped.

Length ratio of pleomeres 1–6 measured along midline 1.0: 1.9: 1.1: 1.0: 1.2: 1.8 ( Fig.1A, C View FIGURE 1 ). Pleomere 1 ( Fig. 1A View FIGURE 1 ) narrowing anteriorly in dorsal view; pleuron with clearly delimited ventral margin. Pleomere 2 ( Fig. 1A, C, D View FIGURE 1 ) approximately as long as wide, pleuron having posterolateral margin distinctly expanded. Pleura of pleomeres 3–5 each with patch of long setae and few dorsal setae on either side; posterolateral margins slightly expanded. Pleomere 6 ( Figs. 1A View FIGURE 1 , 2E View FIGURE 2 ) 1.4 times longer than wide, trapezoidal, slightly narrowly posteriorly and some tufts of long setae; lateral margins each with shallow notch on posterior one-third.

Telson ( Figs. 1A View FIGURE 1 , 2 View FIGURE 2 E–F) approximately as long as wide, narrowing posteriorly; lateral margins each with very low convexity proximally, and thereafter gently convex; posterior margin faintly concave medially, with minute median spine; dorsal surface slightly convex, smooth.

Eyestalks ( Figs. 1A, B View FIGURE 1 ) narrowly separated, reaching beyond mid-length of article 1 of antennular peduncle, about 2 times as long as broad; outer margins strongly sinuous, convex part corresponding to cornea, terminating in dorsoventrally flattened lobe bearing 2 minute denticles or tubercles on terminal margin. Cornea black, large, situated dorsolaterally in midlength of eyestalk, about 0.3–0.5 width of eyestalk; no extra-corneal pigmentation evident.

Antennular peduncle ( Fig. 1F View FIGURE 1 ) thicker, but shorter than antennal peduncle; article 2 slightly shorter than article 1; article 3 twice as long as article 2. Flagella subequal in length to entire peduncle; lower ramus slightly longer, than upper ramus, with much denser and longer setation.

Antennal peduncle ( Fig. 1E View FIGURE 1 ) with article 2 as long as article 1; article 3 short; scaphocerite vestigial; article 4 longer than proximal 3 articles combined; article 5 as long as and narrower than article 4.

Mouthparts typical for genus according to external observation, not illustrated. Maxilliped 3 ( Fig. 3B View FIGURE 3 ) without exopod; ischium-merus not particularly broadened, subrectangular in general shape; ischium 1.5 times as long as broad, mesial surface with well-developed crista dentata consisting of row of small teeth; merus subtriangular, narrowing distally, 1.3 times as broad as long; carpus triangular, becoming wider distally, longer than broad; propodus large, ovoid, as broad as long; dactylus narrow, tapering distally, arcuate.

Pereopods 1 (chelipeds) unequal and dissimilar, larger cheliped right or left. Larger cheliped ( Fig. 2 View FIGURE 2 A–D) with ischium slender (about 5.0 times as long as broad), slightly sinuous with distal part sloping, ventral margin with row of small tubercles. Merus about 2 times as long as wide; upper margin gently convex, distinctly carinate over entire length; outer face divided into 2 facets by longitudinal median carina; lower margin devoid of prominent hook-like process, bicarinate, outer carina weakly tuberculate, inner carina with row of more conspicuous, distally inclined teeth. Carpus wide, about 1.5 times higher than long, subquadrate, upper and lower margins sharply keeled, upper and lower margins distally diverging, terminating in subacute angular upper corner and truncate lower corner; mesial surface concave with upturned upper margin and wide concavity accommodating distal part of merus when cheliped flexed, and with deep oblique groove on lower distal part. Propodus heavy, about 2 times as long as broad; inner surface of palm proximally smooth, several tufts of long setae on upper part; upper margin carinate in proximal one-third, rounded in distal two-thirds; lower margin serrated with row of small tubercles, not extending onto fixed finger, and with rows of tufts of long setae extending onto fixed finger; distal margin inferior to base of dactylus concave. Fingers without hiatus when closed, fixed finger almost straight; dactylus subequal in length to palm, terminating in hooked tip crossing inner side of fixed finger; outer and inner surfaces with tufts of long setae arranged in longitudinal rows.

Smaller cheliped ( Fig. 3A View FIGURE 3 ) shorter, much more slender than larger cheliped. Ischium about 3.0 times as long as wide; upper margin nearly straight, unarmed; lower margin concave, also unarmed. Merus about 2 times as long as broad; upper margin slightly convex; lower margin also convex. Carpus subtrapezoidal, widened distally; upper margin carinate, terminating in angular corner; lower and proximal margins sharply carinate, with few tufts of setae. Palm almost as long as carpus, slightly longer than high; outer and inner surfaces similarly convex, glabrous. Fixed finger terminating in small corneous claw. Dactylus curving, crossing inner side of fixed finger; upper surface with short blunt carina proximally on outer side; outer surface with row of tufts of long setae along upper and occlusal margin.

Pereopod 2 ( Fig. 3C View FIGURE 3 ) chelate. Ischium short, dorsal margin nearly straight, ventral margin slightly concave. Merus 2.5 times as long as ischium, about 3.0 times as long as greatest width; dorsal margin nearly straight except for sloping distal part; ventral margin slightly sinuous, with row of long setae. Carpus subtriangular, 2.5 times as long as wide, with dense setae proximoventrally. Chela triangular, with dense setae on ventral margin. Dactylus with dense setae on dorsal margin; cutting edge straight, unarmed.

Pereopod 3 ( Fig. 3D View FIGURE 3 ) strongly compressed laterally. Ischium 2 times as long as wide, as wide as merus. Merus 2 times as long as ischium, 3.2 times as long as wide. Carpus subtriangular, distal margin slightly bi-lobed, with tufts of long setae at each angle. Propodus wider than carpus, subovate, with row of numerous setae, becoming longer proximally, about 2 times as long as wide. Dactylus triangular, much shorter than propodus.

Pereopod 4 ( Fig. 3E View FIGURE 3 ) semi-chelate. Ischium short, 1.4 times as long as wide. Merus 2.2 times as long as ischium, 2.8 times as long as wide. Carpus longer than propodus, 3.2 times long as wide. Propodus shorter than carpus. Dactylus terminating in narrow tip.

Pereopod 5 ( Fig. 3F View FIGURE 3 ) moderately slender, chelate, longer than pereopods 2–4. Merus about 2 times as long as ischium. Carpus slightly shorter than propodus. Propodus with dense setae on distal part. Dactylus curved, partially obscured by dense setae.

Male pleopod 1 ( Fig. 4A View FIGURE 4 ) uniramous, 2-articulated; proximal article widened proximally,1.7 times long as distal article; distal article unequally bilobed distally, mesial lobe distinctly longer than outer lobe, recurved, outer lobe rounded, with sparse long setae. Female pleopod 1 ( Fig. 4C View FIGURE 4 ) consisting of two articles; proximal article slightly widened proximally, distal article shorter than proximal article, terminal margin rounded.

Male pleopod 2 ( Fig. 4B View FIGURE 4 ) biramous, leaf-like, endopod longer than exopod, slightly widened in middle part, without appendix interna. Female pleopod 2 ( Fig.4D View FIGURE 4 ) biramous, endopod broader and longer than exopod, appendix interna rod-like, located on distal part of mesial margin.

Uropodal protopod ( Fig. 2E View FIGURE 2 ) bearing bilobed posterodorsal margin. Endopod elongate sub-semicircular, with distinctly convex outer margin, about 1.2 times as long as broad, and distinctly longer than telson, lateral margin unarmed; mesial margin fringed with setae. Exopod as long as endopod, rounded oblong, 1.3 times as broad as long, bearing well-developed, marginally setose anterodorsal plate.

Habitat. Burrowing in sandy-muddy bottom under boulders.

Species 1 2 3 4 5 6 7 8 9 1. Neocallichirus darvishi (Holotype) -

2. Neocallichirus darvishi (Paratype) 3 -

3. Neocallichirus jousseaumei 13 15 -

4. Sergio mericeae 17 17 17 -

5. Sergio mirim 18 18 19 19 -

6. Sergio guassutinga 17 18 19 16 14 -

7. Callichirus kraussi 20 21 21 19 18 18 -

8. Neotrypaea californiensis 20 21 22 20 18 20 20 - 9. Necallianassa truncata 20 21 23 21 20 20 23 14 - 10. Callichirus sp. 23 22 22 24 15 21 20 19 20

Etymology. The new species is named in memory of Ferdowsi University biosystematics professor, Jamshid Darvish, for his enthusiasm to teach about phylogeny, evolution and biodiversity.

Remarks. The present new species agrees with the generic diagnosis of Neocallichirus ( Sakai 1988; Manning & Felder 1991), particularly in the antennular peduncle being shorter than the antennal peduncle, the absence of an exopod on maxilliped 3, the propodus of maxilliped 3 being as broad as long, the major cheliped merus devoid of a hook-like projection on the lower margin, the lack of a conspicuous median cleft on the posterior margin of the telson, and the uropodal endopod being broader than long. Morphologically, it is most similar to N. jousseaumei in the terminally denticulate eyestalks and the carpus of the larger cheliped being much higher than long. Nevertheless, N. darvishi differs from N. jousseaumei in the following characters: (1) the rostrum is more prominent and acuminate in N. darvishi n. sp. than in N. jousseaumei when adults are compared (cf. Fig. 1A, B View FIGURE 1 versus Dworschak 2011: figs 1A, 2A, 3A, 4A); (2) the posterior margin of the telson is armed with a minute median spine in N. darvishi n. sp. ( Fig. 1E, F View FIGURE 1 ), whereas there is no such spine in N. jousseaumei (cf. Dworschak 2011: 7, figs 2L, 3P); (3) in N. darvishi n. sp., the corneal pigmentation is restricted to the dome-like cornea ( Fig. 1B View FIGURE 1 ), whereas in N. jousseaumei , the pigmentation extends outside of the cornea (= extra-corneal pigmentation) (cf. Dworschak 2011: figs. 1A, B, 2A, B, M, N, 3A, C, D, 4A, B); (4) the merus of the major cheliped in N. darvishi n. sp. is about 1.7 times as long as broad (versus 1.2 times as long in N. jousseaumei ) ( Fig. 2A, B View FIGURE 2 and Dworschak 2011: figs. 1D, E; 2D, R; 3L; 4E, F); (5) the distal article of the male pleopod 1 is much more slender and greatly unequally bilobed in N. darvishi n. sp. (cf. Fig. 4A View FIGURE 4 versus Dworschak 2011: figs 1L, 3Q, 4G–I); (6) the uropodal endopod is about 1.5 times as long as broad in N. darvishi n. sp. (versus about 1.1 times as long in N. jousseaumei ) ( Fig. 2E View FIGURE 2 and Dworschak 2011: figs 2L, 3P, 4D). Furthermore, the maximum body size is greatly different between the two species. Neocallichirus darvishi n. sp. is much smaller than N. jousseaumei . The ovigerous female of the new species is 9.1 mm cl, whereas the smallest ovigerous female of N. jousseaumei is 15.6 mm cl ( Dworschak 2014). The mitochondrial COI divergence between the new species and N. jousseaumei is 13–15% (mean 14%), well supporting the recognition of the new species ( Table 2).