Periclimenaeus ascidiarum Holthuis, 1951b

Fransen, Charles H. J. M., 2023, The marine palaemonid shrimps (Crustacea, Deapoda, Caridea) of the Dutch Caribbean, Zootaxa 5387 (1), pp. 1-127 : 33-36

Periclimenaeus ascidiarum Holthuis, 1951b

( Figs. 10–15 , video 6)

Material examined. Bonaire: Stn BON.10, Salt Pier, 12°05.006′N 068°16.912′W, 26.x.2019, depth 7 m, in compound ascidian, Diplosoma sp. , not collected, photo C.H.J.M. Fransen. RMNH. CRUS.D.57887: 1 ovigerous female, pocl. 2.3 mm; stn BON.18, Red Slave, 12°01.605′N, 068°15.079′W, 28.x.2019, depth 8 m, in greyish compound ascidian under stone, Diplosoma sp. , collected by C.H.J.M. Fransen (fcn. BON.18-5) (video 6). RMNH. CRUS.D.58128: 1 male, pocl. 1.2 mm; 1 female, pocl. 1.3 mm, all R =3/0; stn BON.27, Red Slave, 12°01.592′N 068°15.063′W, 03.xi.2019, depth 1 m, snorkeling, in greyish compound ascidian under stone, Diplosoma sp. , collected by W. de Gier. RMNH. CRUS.D.57909: 1 ovigerous female, pocl. 1.7 mm, R =3/0; stn BON.37, Andrea I, 12°11.285′N 068°17.795′W, 06.xi.2019, depth unknown, scuba diving, in greyish compound ascidian under stone, Diplosoma sp. , collected by C.H.J.M. Fransen (fcn. BON.34-4). Comparative material. RMNH. CRUS.D.51396, 1 ovigerous female, pocl. 1.4 mm; USA, SE Florida, N coast of Miami, 1976, collected by R. Guest.

Remarks. The morphological characters of the present specimens agree very well with the original description of Holthuis (1951b) and diagnosis in Ferreira et al. (2020). Rostrum with three dorsal teeth, without ventral teeth, distally upturned, overreaching cornea and basal segment of antennular peduncle (figs. 10A–C, 14A). Carapace without supraorbital tooth or tubercle; antennal tooth robust. Inferior orbital angle strongly produced ( Fig. 10B ). Pterygostomial angle produced ( Fig. 10A ). Scaphocerite short, reaching distal margin of penultimate segment of antennular peduncle; distolateral tooth distinct but not overreaching distal margin of lamina ( Fig. 10B ). Carpocerite distinctly overreaching distal margin of scaphocerite ( Fig. 10B , 11A ). Second pereiopods unequal in size and shape, without tubercles (figs. 11B, D). Major second chela ( Fig. 11B, C ) distal cutting edge of dacylus finely denticulate; distal cutting edge of fixed finger entire ( Fig. 11C ); fixed finger slightly overreaching dactylus. Minor cheliped fingers with denticulated tooth in proximal part, distal part of cutting edge finely denticulate, more extensive in dactylus than in fixed finger ( Fig. 11E–G ). Ambulatory pereiopods similar with distoventral part of propodus (figs. 12A–D, 13A, B, 14B–G) with one subdistal ventral and pair of distoventral spines; dactyli biunguiculate with posterior acute process on flexor margin of corpus (figs. 12A–D, 13A, B, 14B–G); fifth pereiopods with distolateral half with rows of serrulate setae ( Figs. 13A , 14F ). First abdominal segment without median anterior dorsal lobe. Sixth abdominal segment with posterolateral margin with small tooth ( Fig. 10E ). Distolateral tooth of exopod of uropod distinct with mobile spine medially; mobile spine about twice as long as distolateral tooth ( Fig. 10F ). Both pairs of dorsal spines of telson located in proximal half, anterial par submedian, posterior pair submarginal; lateral pair of distal spines in line with other distal spines, not subdistal or submarginal ( Fig. 10D, E ).

Colour ( Fig. 12 ). Colour pattern similar to that figured by Pachelle et al. (2018: fig. 2).

Ecology. Known as an endosymbiont, living in the cloacal cavity of unidentified compound ascidians ( Holthuis, 1951b) and a compound ascidian of the genus Diplosoma ( Ferreira et al. 2020) .

Distribution. Known from Florida and Colombia ( Holthuis 1951b), Dominica ( Chace 1972), Cuba ( Martínez-Iglesias 1986), Caribbean coast of Panama ( Pachelle et al. 2018), Los Roques ( Rodriguez 1986) to Brazil ( Vieira et al. 2012, Ferreira et al. 2020) in depths of 1– 73 m. This is the first record of the species for Bonaire.

Figures

FIGURE 10. Periclimenaeus ascidiarum Holthuis, 1951b, RMNH.CRUS.D.57887, ovigerous female, pocl. 2.3 mm.A, anterior appendages, lateral view; B, idem, dorsal view; rostrum; C, rostrum; D, telson, dorsal view; E, tailfan; F, uropodal exopod, distolateral part; G, right antennula, dorsal view. Scale bars: A–C, E=1.0 mm; D, F, G=0.5 mm.

FIGURE 11. Periclimenaeus ascidiarum Holthuis, 1951b, RMNH.CRUS.D.57887, ovigerous female, pocl. 2.3 mm. A, left antenna, ventral view; B, left major second pereiopod, mesial view; C, idem, chela; D, rigth minor second pereiopod, mesial view; E, idem, chela; F, idem, distal part fingers, setae omitted; G, idem, lateral view. Scale bars: A=0.5 mm, B, D=4.0 mm, C, E=1.0 mm; F, G=0.25 mm.

FIGURE 12. Periclimenaeus ascidiarum Holthuis, 1951b, RMNH.CRUS.D.57887, ovigerous female, pocl. 2.3 mm. A, right, third pereiopod, mesial view; B, idem, distal part propodus and dactylus; C, right fourth pereiopod, mesial view; D, idem, distal part propodus and dactylus. Scale A, C=1.25 mm, B, D=0.125 mm.

FIGURE 13. Periclimenaeus ascidiarum Holthuis, 1951b, RMNH.CRUS.D.57887, ovigerous female, pocl. 2.3 mm. A, right fifth pereiopod, mesial view; D, idem, distal part propodus and dactylus. Scale A=1.25 mm; B=0.125 mm.

FIGURE 14. Periclimenaeus ascidiarum Holthuis, 1951b, RMNH.CRUS.D.57909, ovigerous female, pocl. 1.7 mm.A, rostrum; B, right third pereiopod, mesial view; C, idem, dactylus and distal part propodus; D, right fourth pereiopod; E, idem, dactylus and distal part propodus; F, right fifth pereiopod; G, idem, dactylus and distal part propodus. Scale: A=1.0 mm; B, D, F=1.25 mm; C, E, G=0.125 mm.

FIGURE 15. Periclimenaeus ascidiarum Holthuis, 1951b. A, B, stn BON.10, Bonaire, Salt Pier, 12°05,006′N 068°16,912′W, 26.x.2019, depth 7 m, in compound ascidian, Diplosoma sp.; C, RMNH.CRUS.D.57887, ovigerous female, stn BON.18, Red Slave, 12°01.605′N, 068°15.079′W, 28.x.2019, depth 8 m, from greyish compound ascidian, Diplosoma sp. under stone. A, habitus removed from host; B, idem, near host; C, ovigerous female, dorsal view, major second cheliped missing. (Photographs by C.H.J.M. Fransen.)