Palaemonella orientalis Dana, 1852

Fransen, Charles H. J. M., Veer, Eva Van Der & Frolová, Pavlína, 2022, A new species of scleractinian associated shrimp of the genus Palaemonella (Crustacea, Decapoda, Palaemonidae) with a redescription of Palaemonella orientalis Dana, 1852, Zootaxa 5214 (4), pp. 557-580 : 568-578

Palaemonella orientalis Dana, 1852

( Figs. 9–16 )

Palaemonella orientalis Dana, 1852a: 26 ; Dana, 1852b: 583; Weitenweber, 1854: 60; Dana, 1855 (atlas): 12, pl. 38 fig. 4;? De Man, 1888: 552; Borradaile, 1917: 358 (listed); Kemp, 1922: 131–134, figs. 9–11; Edmondson, 1925: 8;? Edmondson, 1933: 212, fig. 124c;? Edmondson, 1946: 252, fig. 152c.

Vir orientalis — Holthuis, 1952: 8, 30 (full synonymy); Holthuis, 1953: 55; Holthuis, 1955: 57, fig. 31b (listed); Cloud, 1959:

436 (listed); Bruce, 1972a: 65, fig. 1; Bruce, 1972b: 403–405; Hipeau-Jacquotte, 1972: 8 (listed); Bruce, 1976a: 5; Bruce, 1976b: 95, 144; Bruce, 1976c: 485; Bruce, 1977: 2 (listed); Bruce, 1979: 218; Bruce, 1981: 79; Bruce, 1984: 144; Bruce, 1990: 13, 17, 19 (listed); Chace & Bruce, 1993: 64, 131–132; Fransen, 1994: 141 (in part, only RMNH.CRUS.D.42991); De Grave, 2000: 144; Hayashi, 2001: 62, fig. 406a–d; Bruce, 2003: 246 (listed); Fransen & Holthuis, 2007: 101 (listed); Li et al., 2007: 305, fig. 157 (listed).

non Palaemonella orientalis — Spence Bate, 1888: 787, pl. 128 fig. 4; Estampador, 1937: 48. (= Periclimenes batei ( Borradaile, 1917 )).

non Palaemonella orientalis — Rathbun, 1906: 925. (= Brachycarpus biunguiculatus (H. Lucas, 1846)) .

Material examined. MNHN-IU-2022-2001: 2 males, pocl. 2.0 and 2.2mm; 1 damaged specimen, pocl. 1.9mm; stn FR18, Vanuatu, Santo, NW Tutuba Island, 15°19′47.892″S, 167°10′1.128″E, 18.ix.2006, depth unknown, steep reef slope, collected by C.H.J.M. Fransen, GenBank accession no. OP326600 (16S). RMNH. CRUS.D.58034: 1 ovigerous female, pocl. 2.3mm: stn MAL.19.068. Maldives, N Nilandhe Atoll, Magoodhoo Island, lagoon in front of station, 3°4′51.92″N, 72°57′57.74″E, 15.v.2014, depth 0–2 m, among Pocillopora spec. and Acropora spec. , collected by C.H.J.M. Fransen, GenBank accession no. OP326601 (16S). RMNH. CRUS.D.58035: 1 ovigerous female pocl. 1.9mm: stn LEM.25, Indonesia, NE Sulawesi, Lembeh Strait, N Pulau Dua, 1°23′28.6434″N, 125°12′58.7154″E, 13.ii.2012, depth 11 m, on Acropora spec. , collected by Zoi Farenzena, GenBank accession no. OP326602 (16S). RMNH. CRUS.D.42888: 1 juvenile pocl. 1.50mm; NIOP-E, stn. SEY.603, Mahé, SE coat, just S of Pointe au Sel and Ile Souris, 04°44′S 55°32Έ, depth 1 m, sandy reef flat with isolated granitic rock and intertidal beachrock, snorkeling, between branches of Pocillopora damicornis (Linnaeus, 1758) , 7.xii.1992, collected by C.H.J.M. Fransen. Stn. SEM.18, Malaysia, Semporna, Ligitan Isl., Ligitan 4, 04°14′06.5″N 118°48′26.5″E, 4.xii.2010, depth unknown, on Acropora spec. , not collected, photograph by C.H.J.M. Fransen.

Description. Small shrimp of subcylindrical body form. Carapace smooth. Rostrum ( Fig. 9A–C ) well developed, straight, horizontal, reaching distal margin of scaphocerite, with 6–9 acute dorsal teeth on rostrum proper, sometimes proximalmost tooth postorbital; ventral margin with single row of short setae, with 1–2 acute teeth at level of distal margin of ultimate segment of antennular peduncle. Orbit obsolescent ( Fig. 9A–C ); inferior orbital angle slightly produced; antennal spine long, slender, acute and marginal, reaching distal margin of basicerite; hepatic spine absent; anterolateral angle of carapace rounded, not produced.

Abdomen ( Fig. 9D , 16A ) normal, third tergite not produced, sixth segment ( Fig. 9D ) about 1.5 times length of fifth, 1.1 times longer than deep, with posterolateral and posteroventral angles bluntly produced; pleura of first five segments enlarged, broadly rounded ( Fig. 9D ).

Telson ( Fig. 9E ) about 1.6 times longer than sixth abdominal segment, 2.2 times longer than proximal width, lateral margins convergent, sublinear, with two pairs of small subequal dorsal spines at about 0.51 and 0.74 of telson length, distal margin ( Fig. 9F ) 0.29 of proximal margin width, rounded, without median process, lateral spines small, similar to dorsal spines, intermediate spines robust, 4.5 times as long as lateral spines, submedian spines almost half length of intermediate spines, setulose.

Eye ( Fig. 9A ) with whitish globular cornea with red lines, with distinct accessory pigment spot dorsally; cornea almost as wide as maximum width of eyestalk; eyestalk 1.1 times longer than maximum width.

Antennula ( Fig. 10A ) normal; basal segment of antennular peduncle about half as long as scaphocerite, with acute ventromedial tooth, distal margin convex, with plumose setae, distolateral tooth reaching halfway intermediate segment, lateral margin slightly convex, medial margin straight with row of plumose setae, statocyst normal; stylocerite slender, acute, reaching to half segment length; intermediate and distal segments subequal in length, together about 0.5 of basal segment length; flagella long, slender, upper flagellum biramous, proximal 6 segments fused, shorter free ramus with 3 segments, with 12 groups of aesthetascs, longer free ramus slender.

Antenna ( Fig. 10B ) normal; basicerite without distolateral spine; ischiocerite and merocerite normal; carpocerite subcylindrical, reaching to about 0.25 of scaphocerite length; flagellum well developed; scaphocerite extending well beyond antennular peduncle, 3 times longer than maximum width, distal margin rather small, broadly rounded, lateral margin concave with acute distolateral tooth exceeding distal margin of lamina.

Epistome and labrum normal.

Fourth thoracic sternite ( Fig. 9G ) with strong, broad, blunt, median process.

Fifth thoracic sternite ( Fig. 9G ) with shallow lateral plates posteromedial of second pereiopods with triangular submedian processes.

Sixth to eight thoracic sternites unarmed, increasing in width posteriorly.

Mandible ( Fig. 11A–C ) robust, with small one- or two-segmented palp with few small simple setae; molar process stout with large angular teeth and brushes of stout setae; incisor process also stout with three large acute distal teeth.

Maxillula ( Fig. 11D ) with upper lacinia slender, with two rows of robust simple and serrulate spines medially; lower lacinia slender, setose distally; palp distinctly bilobed, upper lobe with single small simple seta, lower lobe with a small, ventral, single, short, recurved seta.

Maxilla ( Fig. 11E ) with basal endite well developed, entire, not bilobed, fringed medially by many long simple and serrulate setae; coxal endite obsolete, median margin straight, without setae; scaphognathite about twice as long as proximal width; palp well developed, basally broad, tapering distally, indistinctly two-segmented, with few plumose setae on lateral border.

First maxilliped ( Fig. 12A ) with basal and coxal endites distinct; basal endite broad, anterolateral border sparsely setose, medial margin straight, with numerous slender simple and serrulate setae; coxal endite medially straight, sparsely setose; exopod well developed, flagellum with about 6 plumose setae distally, caridean lobe small, narrow; coxa with very large bilobed exopod, anterior lobe slightly larger than posterior lobe; palp tapering distally with one large plumose seta subdistally on medial border.

Second maxilliped ( Fig. 12B ) with endopod normally developed; with dactylar segment narrow, 4 times longer than broad, densely fringed with numerous coarsely serrulate, spiniform, and long curled, finely serrulate setae medially; distomedial lobe of propodal segment rounded, with row of long slender simple and serrulate setae, ventrolateral margin devoid of setae; carpal segment distomedially angular, without setae, unarmed; meral segment medially excavate, without setae; basal and ischial segments fused, both segments medially excavate, with few short setae medially; exopod normal, with long plumose setae distally; coxal segment slightly produced medially, with few long setae; epipod small, simple, subrectangular, without podobranch.

Third maxilliped ( Fig. 12C ) with endopod slender, reaching with terminal segment beyond carpocerite; ischiomerus and basis distinct, ischiomerus 6 times longer than wide, flattened and twisted, setose medially, otherwise glabrous, with 2 robust spines in distal part; carpal segment 4.5 times longer than wide, 0.72 of ischiomeral length, subcylindrical, with groups of long serrulate setae medially; terminal segment 0.52 of ischiomeral segment, tapering distally with terminal spine, medial margin with groups of short serrulate setae; basis with few simple setae along slightly convex median margin; exopod well developed, reaching distal margin of ischiomerus, with numerous plumose setae distally; coxa with small medial lobe and rounded epipod laterally.

First pereiopods ( Fig. 13A ) slender, exceeding carpocerite with distal part merus, carpus and chela; chela normal, slightly compressed, palm about twice as long as deep, with several rows of cleaning setae proximoventrally, fingers about as long as palm, slender, tapering, both with brushes of simple setae and hooked tip distally, cutting edges simple, entire; carpus 1.3 times chela length, slender, 6 times longer than distal width, tapering slightly proximally, with several cleaning setae distoventrally; merus about as long as carpus, about 7 times longer than wide; ischium and basis with several long simple setae medially; coxa with small setose ventromedial lobe.

Second pereiopods ( Fig. 13B ) equal and similar; chela ( Fig. 13C ) about 1.6 times carapace length, palm smooth about 3.3 times longer than deep, slightly swollen proximally, fingers ( Fig. 13D ) 0.7 times palm length, slender, dactylus about 5.5 times longer than proximal depth, dorsal margin slightly convex, tip hooked, acute, cutting edge with 2 teeth in proximal half, distal cutting edge entire; fixed finger similar, with 1 large tooth at level between two dactylar teeth and 3–4 small teeth proximally; carpus about 0.4 of chela length, about 5 times longer than distal width, tapering proximally, constricted then flared distally with blunt angular dorsal lobe; merus slightly longer than carpus, 4.3 times longer than central width, armed with distomesial tooth; ischium about 0.75 length of merus, tapering proximally; basis and coxa without special features.

Third pereiopods ( Fig. 14A ) short, rather robust, exceeding carpocerite by carpus, propodus and dactylus; dactylus ( Fig. 14B ) simple, curved, 0.19 of propodus length, 1.7 times longer than proximal depth, corpus 1.1 times longer than proximal width, distal width 0.28 times proximal width, dorsal margin convex, with 3–4 simple setae at about 0.65 of length, ventral margin proximally slightly convex, distally concave, without accessory tooth, without setae; unguis indistinctly demarcated, 0.70 of corpus length, simple, curved, distally acute; propodus almost 7 times longer than wide, slightly compressed, slightly bowed, uniform, with many long slender setae distally, without spines; carpus normal, 0.43 times propodus length, unarmed; merus as long as propodus, 6.4 times longer than wide, uniform, unarmed; ischium, basis and coxa without special features. Fourth pereiopods ( Fig. 14C, D ) similar to third. Fifth pereiopods ( Fig. 15A, B ) similar to third and fourth.

Uropods ( Fig. 9E ) extending beyond telson; protopodite robust, unarmed; exopod with lateral margin straight, non-setose, with small acute posterolateral tooth, slightly bending inward, flanked medially by mobile spine twice as long as posterolaterlal tooth; endopod slightly shorter than exopod.

Pleopods with endopods shorter than exopods.

Ova about 50, size 0.45mm.

First pleopod of female ( Fig. 15C ) with endopod less than half as long as exopod, with many long plumose setae medially and distally.

Male endopod of first pleopod ( Fig. 15D ) half as long as exopod, about 3.5 times longer than wide, with median margin concave, distally slightly expanded, with relatively short plumose marginal setae. Endopod of second pleopod ( Fig. 15E ) 0.8 times length of exopod; appendix masculina well developed, with several rows of strong serrulate setae, about as long as appendix interna.

Size. Maximal pocl. in males 2.2mm, in ovigerous females 2.3mm.

Coloration ( Fig. 16 ). Body translucent with white and orange chromatophores. Appendages translucent with white chromatophores at joints. Eyestalks with orange and white longitudinal lines of chromatophores anteriorly. Eyes whitish with red lines and black spot dorsally. White spots at base of uropods.

Host. Scleractinia : Pocilloporidae : Pocillopora damicornis (Linnaeus, 1758) ( Bruce, 1972a, b; 1976c; 1981; Fransen, 1994); Pocillopora verrucosa (Ellis & Solander, 1786) ( Bruce, 1976c; 1984) Stylophora erythraea Von Marenzeller, 1907 ( Bruce, 1972b) ; Stylophora pistillata (Esper, 1792) ( Bruce, 1972b) . Acroporidae : Acropora spec. ( Bruce, 1976 a, 1976b; De Grave, 2000);

Distribution. Type locality ‘in mari Suluensi’ ( Dana, 1852a). Recorded from ‘Indischen Archipel’ (De Man, 1888); Fiji ( Bruce, 1972 a, 1981); Fort Blair, Andaman Islands ( Kemp, 1922);? Hawaii ( Edmondson, 1925, 1946); Pumgume reef, Murogo reef, Zanzibar and Bamburi, Kenya ( Bruce, 1976c); Seychelles ( Bruce, 1976b; 1984; Fransen, 1994); Watamu, Kenya ( Bruce, 1976a); Macclesfield Bank, South China Sea ( Bruce, 1979); Osprey Reef, Coral Sea, Australia ( Bruce, 1990); Philippines ( Chace & Bruce, 1993); Mariana Islands ( Holthuis, 1953); Japan ( Hayashi, 2001); Hansa Bay, Papua New Guinea ( De Grave, 2000). Now recorded for the first time from the Maldives, Sulawesi ( Indonesia), Semporna ( Malaysia), and Vanuatu.

Remarks. The type description by Dana (1852a) in Latin is brief. It is stated that the rostrum is straight, not overreaching the antennal scales and bears 6 teeth dorsally and one ventrally. On plate 38, fig. 4a of the Atlas published by Dana in 1855, the large antennal tooth and the absence of a hepatic tooth are evident; fig. 4b shows the two-jointed palp on the mandible; fig. 4c and d show the second and third maxillipeds which are similar to those in the present material ( Fig. 12B, C ).

De Man (1888) describes two specimens collected from crinoids in the “Indischen Archipel’. De Man noted the absence of the hepatic spine in his specimens. Bruce (1976b) considered the association of the specimens with crinoids erroneous.

Kemp (1922) re-describes the species on the basis of a single specimen from the Andaman Islands. The features described and figured by Kemp (1922) match the characteristics of the present material. The position of the ventral rostral spine halfway the ventral margin of the rostrum is typical for the species. The mandible has an unsegmented palp as in the present specimen from Vanuatu ( Fig. 11C ).

Edmondson (1933, 1946) listed the species form Hawaii. His figure 152c from the 1946 edition, depicting the rostrum and carapace however, shows the presence of a hepatic tooth and a rostrum with 3 ventral teeth. Therefore the specimen he figured cannot be P. orientalis . If this record is based on the same specimen listed by Edmondson in 1925 from Hawaii it is doubtful if the species occurs in Hawaii.

The description and figures of the specimens studied by Bruce (1972a) show identical features compared with the present material.

Figures

FIGURE 9. Palaemonella orientalis Dana, 1852. A, B, D, G, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034; C, E, F male pocl. 2.2mm, MNHN-IU-2022-2001. A, carapace and anterior appendages, lateral view; B, C, rostrum, lateral view; D, abdominal segments 4–6 and caudal pan, lateral view; E, caudal fan, dorsal view; F, telson, tip, dorsal view; G, fourth and fifth thoracic sternites, ventral view. Scale A = 2mm; B–D, G = 1mm; E = 0.5mm; F = 0.25mm.

FIGURE 10. Palaemonella orientalis Dana, 1852, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034. A, right antennula, dorsal view; B, right antenna, ventral view. Scale = 0.5mm.

FIGURE 11. Palaemonella orientalis Dana, 1852.A, B, D, E, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034. C, male pocl. 2.2mm, MNHN-IU-2022-2001. A, left mandible, dorsal view; B, C, left mandible, ventral view; D, left maxillula, dorsal view; E, left maxilla, dorsal view. Scale = 0.25mm.

FIGURE 12. Palaemonella orientalis Dana, 1852, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034. A, left first maxilliped, ventral view; B, left second maxilliped, ventral view; C, left third maxilliped, ventral view. Scale = 0.5mm.

FIGURE 13. Palaemonella orientalis Dana, 1852, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034. A, left first pereiopod; B, left second pereiopod; C, idem, chela; D, idem, fingers. Scale A, D = 0.5mm; B = 2mm; C = 1.25mm.

FIGURE 14. Palaemonella orientalis Dana, 1852, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034.A, left third pereiopod; B, idem, dactylus; C, left fourth pereiopod; D, idem, dactylus. Scale A, C = 1.25mm; B, D = 0.125mm.

FIGURE 15. Palaemonella orientalis Dana, 1852. A–C, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034. D, E, male pocl. 2.2mm, MNHN-IU-2022-2001. A, left fifth pereiopod; B, idem, dactylus; C, D, right first pleopod; E, right second pleopod. Scale A = 1.25mm; B = 0.125mm; C–E = 0.25mm.

FIGURE 16. Palaemonella orientalis Dana, 1852. A, ovigerous female pocl. 2.3mm, RMNH.CRUS.D.58034, stn MAL.19.068, Maldives, N Nilandhe Atoll, Magoodhoo Island, lagoon in front of station, 3°4′51.92″N, 72°57′57.74″E, 15.v.2014; B, C, stn. SEM.18, Malaysia, Semporna, Ligitan Isl., Ligitan 4, 04°14′06.5″N 118°48′26.5″E, 4.xii.2010. Photographs, C.H.J.M. Fransen.