Parabetaeus hummelincki ( Schmitt, 1936 )

Anker, Arthur, 2007, New species and records of alpheid shrimps, genera Salmoneus Holthuis and Parabetaeus Coutière, from the tropical western Atlantic (Decapoda, Caridea), Zootaxa 1653, pp. 21-39 : 34-35

Parabetaeus hummelincki ( Schmitt, 1936)

Fig. 7 , 8 b, c

Alpheopsis hummelincki Schmitt, 1936: 364 .

Neoalpheopsis euryone – Manning & Chace, 1990: 17.

Neoalpheopsis hummelincki – Chace, 1972: 78; Rodríguez, 1980: 137. Neoalpheopsis sp. – Rodríguez, 1986: 176.

Material examined: 1 ovig. female, MNRJ 20217, Brazil, Atol das Rocas , near Barretão, in tide pools and nodules of calcareous algae, coll. P.S. Young, P.C. Paiva and A.A. Aguiar, 27 Aug 2000 [specimen dissected]; 1 ovig. female (with missing chelipeds), USNM 310832, Brazil, off Vitória, Trindade, between Baixa do Sueste and Parcel das Tartarugas, 20°30’S, 29°20’W, in tide pool, rotenone, depth 1–2 m, collector unknown, 16 Jan 1976; 1 male, holotype of Alpheopsis hummelincki , USNM 67395, Bonaire, Kralendijk, under sandy coral debris, coll. P. Hummelinck, 6 Nov 1930; 1 female, MNHN-Na 16391, Dominican Republic, Bayahibe, from coral rocks, depth 1–2 m, coll. A. Anker, 2–3 Jan 2005; 1 male, USNM 256789, Ascension Island, McArthur Point, poisoned isolated tide pool, coll. R.B. Manning et al., 15 Jul 1976.

Comparative material: Parabetaeus cf. euryone (De Man, 1910) : 1 female, USNM 216068, Galapagos, Isla Isabela, Bahía Cartago, R/V Velero III, 13 Feb 1933. Parabetaeus euryone : 1 female, MNHN-Na 13633, parasitized by rhizocephalan ( Thompsonia sp.?), Japan, Ryukyu Archipelago, Kerama group, Yakabi-jima, depth 10 m, coll. K. Nomura, 24 Apr 1994; 1 female, QM W-21828, Hawaii, Oahu, coll. R. Holcom, no further data, det. A. J. Bruce, 26 Oct 1996.

Description: See Schmitt (1936, as Alpheopsis hummelincki ).

Colour: The young female from the DR ( Fig. 8 b) had pale red bands across the abdomen and was generally very similar to the ovigerous female from Bermuda ( Fig. 8 c). The obviously larger ovigerous female photographed in situ off St. Vincent had a more intense red banding and bright yellow eggs ( Fig. 8 d).

Size: The largest western Atlantic specimen examined is the ovigerous female from AR, with CL 6.9 mm, TL 22.0 mm.

Ecology: Coarse sand, sand/rubble and reef bottoms, from the lower intertidal to probably at least 10 m, under rubble and rocks, occasionally also in empty Strombus shells ( Rodríguez, 1986). The AR specimen was found in a tide pool, among nodules of calcareous algae, whereas the DR specimen was extracted from a crevice of a coral rock collected at about 1– 2 m.

Behaviour: Parabetaeus species may carry chelipeds either extended forward ( Fig. 8 c), like species of the presumably related genus Alpheopsis Coutière, 1896 , or folded beneath the body ( Fig. 8 d).

Type locality: Bonaire, Netherlands Antilles.

Distribution: Western Atlantic: Bermuda (present study), southern Caribbean: Netherlands Antilles ( Schmitt, 1936), Venezuela: Los Roques ( Rodríguez, 1986); St. Vincent; Dominican Republic (present study); Brazil: Atol das Rocas and Trindade (present study). Central Atlantic: Ascension Island ( Manning & Chace, 1990).

Remarks: Banner and Banner (1985) placed the western Atlantic Alpheopsis hummelincki Schmitt, 1936 (now Parabetaeus hummelincki ) and the Hawaiian Neoalpheopsis hiatti Banner, 1953 (now Parabetaeus hiatti ) in synonymy of the presumably pantropical Neoalpheopsis euryone De Man, 1910 (now Parabetaeus euryone ), originally described from Indonesia. Nomura & Anker (2001) pointed out that the taxonomic status and synonymy of these two nominal species remain questionable. There appears to be some variation in the shape of the frontal margin (orbital spines, rostrum); the proportions of the telson and pereiopods; the development of the posteromedian triangular piece on the telson; the degree of asymmetry of the chelipeds; the dentition on the cheliped fingers; and some other features, all suggesting that there may be more than one variable pantropical species. Therefore, P. hummelincki and P. hiatti should be treated as valid species, awaiting a combined morphological/molecular revision of the entire P. e u r y o n e complex.

Figures

FIGURE 7. Parabetaeus hummelincki (Schmitt, 1936), ovigerous female from Atol das Rocas, Brazil (MNRJ 20217): a—frontal region, dorsal view; b—same, lateral view; c—third maxilliped, lateral view; d—same, tip of ultimate segment; e—right cheliped, lateral view; f—same, chela fingers, mesial view; g—same, ischium to carpus, dorsal view; hsecond pereiopod, lateral view; i—third pereiopod, lateral view; j—posterior abdominal somites and tail fan, lateral view; k—telson, dorsal view. Scale bars = 1 mm.

FIGURE 8. Habitus and colour patterns: a— Salmoneus teres Manning & Chace, 1990, non-ovigerous specimen (male?) from Guadeloupe (MNHN-Na 13712) (photograph by Frédéric Fasquel); b – d— Parabetaeus hummelincki (Schmitt, 1936): b—young female from Bayahibe, Dominican Republic (MNHN-Na 16391); c—ovigerous female from Bermuda (specimen in BAMZ [not examined], photograph by Wolfgang Sterrer); d—ovigerous female from St. Vincent, photographed in situ at a depth of about 8 m; specimen not collected (photograph by Andrew J. Martinez).