(Figure 5)
Hippolysmata grabhami Gordon, 1935: 319, figs. 10, 11.
Lysmata grabhami — Gasparini et al. 2005: 2897 (appendix 2); Kassuga et al. 2015: 936, figs. 1, 2 (map); Gurjão & Lotufo 2018: 9 (table 2).
Lysmata amboinensis— Chace 1972: 128; Holthuis et al. 1980: 31 [not L. amboinensis De Man, 1888].
Material examined. Brazil: 1 non-ov. specimen (pocl 12.0 mm) MZUSP 39093, Ceará, locality unknown, collector unknown, purchased from aquarium shop in São Paulo, xi.2018; 1 non-ov. specimen (pocl 13.5 mm), MZUSP 36814, Bahia, locality unknown, collector unknown, purchased from aquarium shop in São Paulo, i.2008; 3 non-ov. specimens (pocl 12.0– 10.2 mm), MZUSP 36815, Bahia, locality unknown, collector unknown, purchased from aquarium shop in São Paulo, vi.2017; 3 non-ov. specimens (pocl 10.2– 7.8 mm), MZUSP 36816, same collection data as for previous specimens; 2 non-ov. specimens (pocl 12.5, 11.0 mm), MZUSP 38793, same collection data as for previous specimens, vii.2018; 4 non-ov. specimens (pocl 10.0–8.0 mm), MZUSP 38794, same collection data as for previous specimens; 1 non-ov. specimen (pocl 8.0 mm), MZUSP 38803, same collection data as for previous specimens; 1 non-ov. specimen (pocl 9.5 mm), MZUSP 39105, same collection data as for previous specimen, x.2018.
First record for Brazil. Pernambuco: São Pedro and São Paulo Archipelago (Holthuis et al. 1980, as L. amboinensis).
Distribution. Eastern Atlantic: Madeira, Canary Islands, Cape Verde, Gulf of Guinea. Central Atlantic: Ascension Island and St. Helena. Western Atlantic: Bermuda, Gulf of Mexico, Florida Keys, Bahamas, Antigua and Barbuda, Lesser Antilles, Bonaire, Brazil (Ceará, Pernambuco: São Pedro and São Paulo Archipelago, Bahia and Espírito Santo: off Vitória and Trindade Island) (Holthuis et al. 1980, as L. amboinensis; Kassuga et al. 2015; De Grave et al. 2019; present study) (Fig. 16).
Ecology. Offshore rocky and coral reefs, well-known cleaner of coral and rocky reef fishes, typical depth range: 5–40 m (Holthuis et al. 1980; Kassuga et al. 2015).
Remarks. Lysmata grabhami is morphologically almost identical to L. amboinensis and was considered to be a junior synonym of L. amboinensis by Hayashi (1975). However, Manning & Chace (1990) stated that based on some slight but consistent differences in the colour pattern, both species are valid. In L. grabhami, the posterior margin of the sixth pleonite lacks a transverse white band (present in L. amboinensis), whereas the uropodal exopod presents a continuous white stripe along the lateral margin (versus with two white spots in L. amboinensis) (Baeza 2010: fig. 3).
Among the Brazilian species of Lysmata, L. grabhami shares some morphological features with L. vittata, such as the pterygostomial margin of the carapace with a sharp tooth, scaphocerite as long as or slightly shorter than the antennular peduncle, and the accessory ramus of the lateral antennular flagellum with a single free article (cf. Figs. 5A, E, F; 15A, E, F). However, they can be easily separated from each other by the length of the stylocerite, not reaching the distal margin of the cornea in L. grabhami (Fig. 5A) versus reaching it in L. vittata (Fig. 15A). In L. grabhami, the second article of the antennular peduncle is about as long as the first article (Fig. 5A), whilst in L. vittata, the second article is noticeably shorter, less than half-length of the first article (Fig. 15A). The first pereopod carpus in L. grabhami is also longer, about five times as long as wide in lateral view (Fig. 5G), versus about three times as long as wide in lateral view in L. vittata (Fig. 15G).
As already mentioned, Holthuis et al. (1980) reported L. grabhami for the first time from Brazil (as L. amboinensis), however, based on underwater observations in the remote São Pedro and São Paulo Archipelago. Gasparini et al. (2005) also inferred the presence of L. grabhami in Brazil, without listing any material. The species was formally reported from Brazil only recently, i.e. by Kassuga et al. (2015), based on material from Espírito Santo (off Vitória and Trindade Island). The material from Ceará and Bahia represents the first record of the species for these two Brazilian states.
Lysmata grabhami is one of the most expensive ornamental shrimps marketed in the Brazilian aquarium trade and was included in the list of invertebrates exported from Brazil (Global Marine Ornamental Aquarium Database, GMAD; Gasparini et al. 2005).