Periclimenaeus maxillulidens ( Schmitt, 1936 )

Fransen, Charles H. J. M., 2023, The marine palaemonid shrimps (Crustacea, Deapoda, Caridea) of the Dutch Caribbean, Zootaxa 5387 (1), pp. 1-127 : 53-56

Periclimenaeus maxillulidens ( Schmitt, 1936)

( Figs. 30–32 )

Periclimenes maxillulidens Schmitt, 1936: 371 ( Bonaire).

Periclimenaeus maxillulidens — Holthuis 1951b: 87 (Bonaire); Chace 1972: 28 (Bonaire). Material examined. Bonaire: RMNH.CRUS.D.58148: 1 female, pocl. 1.5 mm, R=2/0; stn BON.15, Red Beryl, 12°02.819′N 068°16.073′W, 28.x.2019, depth 2 m, in greyish compound ascidian under stone, Diplosoma sp. , collected by C.H.J.M. Fransen (photo).

Remarks.The morphological characters of the present two small specimens agree well with the original description by Schmitt (1936) and the descriptions by Holthuis (1951b) and Ferreira et al. (2020). Rostrum ( Fig. 30A, B ) straight with 2 dorsal teeth, without ventral teeth, overreaching distal margin of basal segment of antennular peduncle. Carapace without supraorbital tooth or tubercle; antennal tooth robust, placed at level of inferior orbital angle; inferior orbital angle small, not produced ( Fig. 30B ); pterygostomial angle produced ( Fig. 30A ). Scaphocerite short, not overreaching antennular peduncle; distolateral tooth small, not overreaching distal margin of lamina; carpocerite reaching distal margin of scaphocerite ( Fig. 30B ). First pereiopods short. Second pereiopods unequal in size and shape, without tubercles; distal part of fingers of major second chela ( Fig. 31A ) entire, without fine denticulation; minor cheliped distal part of cutting edge of dactylus finely denticulate ( Fig. 31B ). Third pereiopod ( Fig. 32A ) slightly more robust than fourth; fourth slightly more robust than fifth; propodus of third pereiopod devoid of spines except for tuberculate distoventral pair ( Fig. 32B ). Dactyli of ambulatory pereiopods ( Fig. 32A, B ) not biunguiculate, without proximal process, flexor margin of corpus sinuous; dorsoproximal part of unguis with few scale-like structures ( Fig. 32B ). First abdominal segment without anterior median dorsal lobe. Sixth abdominal somite with posterolateral margin rounded. Telson ( Fig. 30C ) with anterior dorsal pair of spines at about third of length, posterior pair at about two-thirds of length; dorsal spines as long as lateral pair of distal spines; lateral pair of distal spines in line with other distal spines; distal margin entire, without acute median tooth. Distolateral tooth of exopod of uropod distinct with mobile spine medially; mobile spine about twice as long as distolateral tooth ( Fig. 30D ).

Ecology. Its host was unknow until Ferreira et al. (2020) recorded the species inside an ascidian of the genus Diplosoma , which is here confirmed.

Distribution. Known from the tropical western Atlantic. After it was first described from Bonaire ( Schmitt 1936; Holthuis 1951b; Chace 1972), it was recorded from Florida ( Holthuis 1951b) , Yucatan ( Santana-Moreno et al. 2013), Caribbean coast of Panama ( Pachelle et al. 2018), and Espírito Santo, Brazil ( Ferreira et al. 2020), in depths of 1– 46 m.

Figures

FIGURE 30. Periclimenaeus maxillulidens Holthuis, 1951b. RMNH.CRUS.D.58148, female, pocl. 1.5 mm. A, anterior appendages, lateral view; B, idem, dorsal view; C, telson, dorsal view; D, uropodal exopod, distolateral part. Scale bars: A, B=1.0 mm; C=0.5 mm; D=0.125 mm.

FIGURE 31. Periclimenaeus maxillulidens Holthuis, 1951b. RMNH.CRUS.D.58148, female, pocl.1.5 mm. A, left major second pereiopod chela, mesial view; B, right minor second pereiopod chela, mesial view. Scale bar: A=0.5 mm; B=0.25 mm.

FIGURE 32. Periclimenaeus maxillulidens Holthuis, 1951b. RMNH.CRUS.D.58148, female, pocl.1.5 mm. A, third left pereiopod, lateral view; B, idem, dactylus. Scale bar: A=0.25 mm; B=0.125 mm.