Alpheus macellarius Chace, 1988

Anker, Arthur, 2024, Preliminary revision of Alpheus djeddensis Coutière, 1897 species complex, with description of three new species of goby-associated snapping shrimps and taxonomic notes on A. macellarius Chace, 1988 and A. djiboutensis De Man, 1909 (Decapoda: Alpheidae), Zootaxa 5472 (1), pp. 1-63 : 25-30

Alpheus macellarius Chace, 1988

Figs. 15 , 16A, B , 17

(+ Alpheus cf. macellarius : Figs. 16C–H )

Alpheus macellarius Chace, 1988: 35 , figs. 6, 7; Palomar et al. 2004: 1199; Palomar et al. 2005: 173; Nacorda 2008: 15; Holmer & Heilskov 2008: 658; Minemizu 2013: 100, colour photograph; Anker et al. 2015: 306 , fig. 4; Anker & De Grave 2016: 359, fig. 19; Asmus et al. 2022: 212, 216, figs. 6.4, 6.5 (part., burrow).

(?) Alpheus sp. 13.— Minemizu 2000: 86, colour photograph [= A. cf. macellarius , see text].

Not Alpheus macellarius .— Aaron-Cabrillos 2019: 22 [= A. takla Anker, 2023 ].

Material examined. 1 male (cl 11.6 mm), OUMNH. ZC.2014-11-080, Singapore, CMBS sta. IT95, Raffles Lighthouse , intertidal seagrass flat with rubble, low tide, suction pump, in burrow, leg. A. Anker et al., 29.05.2013 (SS-3217) ; 1 male (cl 14.5 mm), OUMNH. ZC.2014-11-081, same collection data as for previous specimen (SIN-181) ; 1 female (cl 6.5 mm), OUMNH. ZC.2014-11-082, Singapore, CMBS sta. YB74, St. John’s Island , DRTech northern lagoon, depth 0–0.5 m, suction pump, in burrow, leg. A. Anker et al., 26.05.2013 (SS-1662) ; 1 female (cl 5.5 mm, tail fan and posterior part of pleon missing due to extremely careless subsampling), FLMNH UF 14035 , Madagascar, Nosy-Bé, east of Helville near CNRO complex, 13°24’24.8”S / 48°17’30.1”E, muddy bay, depth 0.5–1 m, suction pump, in burrow, leg. A. Anker, 24.05.2008 (BMADA-0430) ; 1 male (cl 5.8 mm), FLMNH UF 14484 , same collection data as for previous specimen (NBE-1833) .

Alpheus cf. macellarius : 1 female (cl 8.9 mm), MNHN-IU-2014-6031, Papua New Guinea, Madang, PAPUA NIUGINI sta. PR81, Rempi , 5°01’34.0”S / 145°47’56.4”E, depth 2–15, leg. A. Anker et al., 22.11.2012 (PR81- PZD-325H); 1 specimen (sex and cl indet.), MNHN-IU-2018-778, New Caledonia, Our Planet Reviewed Koumac 2.1 Expedition, sta. KM 603 , Koumac, near Plage Pandop, 20°34.5’S / 164°16.6’E, muddy intertidal flat near mangroves, suction pump, in burrow with Cryptocentrus cf. leucostictus (preserved together), leg. A. Anker, 12.09.2018; 1 female (cl 4.5 mm), MNHN-IU-2018-1020, New Caledonia, Our Planet Reviewed Koumac 2.1 Expedition, sta. KR 607 , 20°38.3’S / 164°12.4’E, subtidal sandflat, suction pump, depth 7–15 m, leg. A. Anker, 05.09.2018; 1 specimen (sex and cl not determined), MNHN-IU-2019-5128, New Caledonia, Our Planet Reviewed Koumac 2.2 Expedition, sta. KM 702 , Koumac, near Route de Pandop , 20°34.2’S / 164°16.6’E, intertidal sandflat near mangroves, suction pump, in burrow, leg. Z. Ďuriš et al., 29.10.2019; 1 ovig. female (cl 7.4 mm), MNHN-IU-2019-2756, same collection data as for previous specimen; 1 ovig. female (cl 10.2 mm), FLMNH UF 37357 , USA, Northern Mariana Islands, Guam, Apra Harbor, tip of Glass Breakwall , 13°27’16.9”N / 144°37’31.8”E, reef slope in outer lagoon, depth 0–18 m, leg. A. Anker, 20.06.2010 ( GUOK10-0913 ) .

Description. See Chace (1988) for a detailed description and illustrations.

Colour pattern. Type A ( A. macellarius ): Background colour ranging from pale yellow to pale greenish; carapace with several transverse (dorsally) and more oblique (laterally), brown or greenish brown bands, often fused into network of interconnecting patches; most bands with irregular edges and smaller colourless areas within; anterolateral bands on each side of orbital hoods darker greyish or bluish green; post-rostral area typically with whitish patch between eyes; pleon with conspicuous transverse banding consisting of two broad, greenish brown bands on each pleonite connecting laterally and defining oval- or square-shaped, dorsal double band or ring; ventrolateral surface of each pleuron deep blue with oblique whitish or yellowish bands; saddle on first pleonite usually very conspicuous, bright orange and yellow; saddle on fourth pleonite small, whitish, more conspicuous in smaller individuals; telson olive brown with bluish tinge distally and often white central patch in proximal half; antennular peduncles reddish orange; stylocerite dusky blue along lateral edge; antennal carpocerite and scaphocerite marked with blue, green-brown and orange, including blue area near lateral edge; antennular and antennal flagella bluish to pale greenish blue; chelipeds bluish with irregular, brown-green or blue-green areas on most of merus and carpus; mesial face of palm of chela mainly greenish brown with smaller pale bluish patches, isolated or interconnecting (in smaller individuals); pollex and dactylus greenish blue or greenish brown proximally, calcified distal portion pink or pale pink-orange; lateral face of chelae with similar, less vivid patches as on mesial face; second to fifth pereiopods blue or bluish, with bright yellow articulations; uropods dominated by blue colour, with some large yellow areas ( Figs. 15 ; 16A, B , 17 ; see also Anker et al. 2015: fig. 4; Anker & De Grave 2016: fig. 19). Type B ( A. cf. macellarius ): Generally similar to type A, but with more irregular bands or rather mix of patchy network and irregular bands on carapace and especially on pleon; saddle on first pleonite with less conspicuous, narrow orange stripe or without it ( Fig. 16C–H ).

Common name. Seagrass goby shrimp.

Type locality. Cebu, Philippines .

Distribution. Indo-West Pacific from Madagascar to the Philippines, Mariana Islands ( Guam, tentatively as A. cf. macellarius ), Thailand (Phuket), Singapore, Indonesia, Papua New Guinea, New Caledonia (tentatively as A. cf. macellarius ), Samoa (record requiring confirmation) ( Chace 1988; Anker 2001b; Anker et al. 2015, 2016; A. Anker, pers. obs.); possibly more than one species involved (see below).

Ecology. Sandflats, usually with silty and/or muddy component, seagrass beds, sometimes mixed with rocks or loose coral rubble, from the lower intertidal to about 10 m; associated with gobies, Cryptocentrus octofasciatus Regan , C. maudae Fowler and C. leptocephalus Bleeker [= C. singapurensis (Herre) ] in the Philippines, Indonesia and Singapore ( Palomar et al. 2004, 2005; Nacorda 2008; Holmer & Heilskov 2008; Anker et al. 2015; Anker & De Grave 2016; Asmus et al. 2022); one of the shrimps identified as A. cf. macellarius ( Fig. 16C, D ) was associated with Cryptocentrus cf. leucostictus (Günther) in New Caledonia ( Fig. 38C ).

Remarks. Alpheus macellarius , including material preliminarily identified as A. cf. macellarius , is remarkably similar to A. djeddensis and A. shukran sp. nov. in most morphological aspects. The main morphological features that can be used to differentiate between A. macellarius and A. djeddensis and A. shukran sp. nov. are (1) the general proportions of the minor chela, which is noticeably more slender in A. macellarius ; (2) the development of the balaeniceps condition on the fingers of the minor chela (balaeniceps setae absent in A. macellarius vs. well developed in both A. djeddensis and A. shukran sp. nov.); (3) the more concave lateral margin of the antennal scaphocerite in A. macellarius , and (4) the presence of a tooth on the distomesial margin of the major cheliped merus in A. macellarius , but not in the other two species (cf. Figs. 3A, K, J , 4A , 5C, D ; Chace 1988: figs. 6a, e, f, 7h, i).

Alpheus macellarius , A. cf. macellarius , A. djeddensis and A. shukran sp. nov. also share many characteristics of their colour patterns, such as: (1) the complex transverse banding on the carapace and pleon (sometimes diffuse banding or a combination of banding and reticulation); (2) the mesial face of major and minor chelae with pale irregular patches on darker greenish, brownish or bluish background; and (3) the bluish legs with yellow or reddish bands near articulations between the articles (cf. Figs. 6–17 ). The most reliable colour difference between A. macellarius and A. djeddensis and A. shukran sp. nov. appears to be the presence of a bright orange band within the white saddle of the first pleonite; this band is particularly conspicuous in larger specimens ( Fig. 15 ; see also Anker et al. 2015: fig. 4), but can be detected in the form of red or yellow patches also in smaller specimens ( Fig. 16A, C, E ). Smaller specimens of A. macellarius and A. cf. macellarius also have a more pronounced white dorsal patch on the fourth pleonite ( Fig. 16 ), which is barely detectable in larger specimens of A. macellarius , and in both larger and smaller specimens of A. djeddensis and A. shukran sp. nov. ( Figs. 6 , 7 , 11 , 13 , 15 ).

In the general proportions of the major and minor chelipeds, as well as in the absence of balaeniceps setae on the minor chela fingers, A. macellarius is also close to A. karplusi (cf. Chace 1988; Anker 2022b). However, these two species can be separated from each other by the much lower carina in A. macellarius , descending to the level of the orbital hoods (vs. rising well above the orbital hoods in lateral view in A. karplusi ); the shape and proportions of the penultimate article of the third maxilliped; and the presence or absence of a sharp tooth on the distomesial margin of the merus of the major cheliped (cf. Anker 2022b: figs. 1B, E, 2C; Chace 1988: figs. 6b, e, 7f, h). In addition, their colour patterns differ significantly, with the dark olive-brown transverse banding in A. macellarius contrasting with the unmistakable rusty red patches in A. karplusi (cf. Anker et al. 2015: fig. 4; Anker & De Grave 2016: fig. 19; Anker 2022b: figs. 3, 4; see also Figs. 15 , 16A, B ).

Specimens from Indonesia and Singapore previously identified as A. macellarius ( Anker et al. 2015; Anker & De Grave 2016) correspond well to the original description of the species based on material from the Philippines collected with “electric light” in Leyte or found on a market in Cebu City in 1909 ( Chace 1988). The lack of information on the colour pattern of the type specimens of A. macellarius and the presence of several morphologically similar species in Indonesia and adjacent areas (see Figs. 36 , 37 and discussion below) add to the uncertainty of the taxonomic identity of this taxon. For the time being, it seems most reasonable to use the name A. macellarius for the species commonly encountered on shallow seagrass flats (often with abundant coral rubble) throughout South-East Asia and the western part of the Indo-Malay Archipelago ( Malaysia, Indonesia, Philippines), and associated with various species of gobies in the genus Cryptocentrus Valenciennes , as listed above ( Palomar et al. 2004, 2005: 173; Nacorda 2008; Nacorda et al. 2008; Anker et al. 2015; Anker & De Grave 2016; Asmus et al. 2022).

In the present study, A. macellarius is recorded for the first time from the southwestern Indian Ocean. The two specimens from Nosy-Bé, Madagascar, are both young (cl 5.5, 5.8 mm), but generally correspond well to Chace’s (1988) description of the species from the Philippines. One of the specimens (FLMNH UF 14035) has a small tooth on the ventromesial margin of the major cheliped merus, whereas such tooth is lacking on both chelipeds of the other specimen (FLMNH UF 14484). Their colour pattern ( Fig. 16A, B ) is generally similar to that of the Indonesian and Singaporean specimens ( Figs. 15 , 17 ; see also Anker et al. 2015; Anker & De Grave 2016).

The specimens from Papua New Guinea, New Caledonia and Guam preliminarily identified as A. cf. macellarius agree in most aspects with the morphological definition of A. macellarius ( Chace 1988) . However, they differ from the typical specimens of A. macellarius from Indonesia and Singapore by their slightly different colour patterns ( Fig. 16C–H ). The main difference of the colour morph A. cf. macellarius is the more irregular banding on the pleon, resulting in a mottled pattern (with larger blotches and spots), compared to the more regular banding in A. macellarius . The ovigerous female from Guam ( Fig. 16G, H ) presents the most extreme mottling / highly diffuse banding. Its colour pattern is more similar to that of the “blue goby-shrimp Alpheus sp. ” in Kuiter & Debelius (2009: 148) from Malaysia and Indonesia, and “ Alpheus sp. 13” in Minemizu (2000: 86), suggesting a wider distribution of this possibly undescribed species. Interestingly, some transitional banding / mottling is seen in some shrimps tentatively identified as A. macellarius based on colour photographs (see, for instance, Fig. 17B–D ).

In summary, both the present material and available in situ colour photographs suggest that A. macellarius may also represent a species complex or at least two closely related species phylogenetically allied to A. djeddensis and A. shukran sp. nov. In fact, some Omani material of the latter species (smaller specimens from east of Muscat) was identified as “ A. macellarius ?” in the field, due to the very similar colour pattern and cheliped shape. Molecular analyses of all material morphologically identifiable as A. macellarius are needed to bring more clarity into this taxon.

Figures

FIGURE 3. Alpheus djeddensis Coutière, 1897, paralectotype, male (cl 18.9 mm) from Jeddah, Saudi Arabia (MNHN-IU-2016- 9011); A, frontal region, dorsal; B, same, lateral; C, telson, dorsal; D, antennal scaphocerite, dorsal; E, third maxilliped, lateral; F, left (major) cheliped, mesial; G, same, lateral; H, same, dactylus, lateral; I; right (minor) cheliped, ischium to proximal portion of propodus (chela palm), lateral; J, same, distal portion of merus carpus and chela, lateral; K, same, chela, mesial; L, second pereiopod, lateral; M, third pereiopod, lateral; N, same, propodus and dactylus, lateral; O, same, dactylus, ventromesial; P, fourth pereiopod, lateral; Q, same, propodus and dactylus, lateral.

FIGURE 4. Alpheus djeddensis Coutière, 1897, male (cl 19.3 mm) from Farasan Islands, Saudi Arabia (FLMNH UF 36913); A, frontal region, dorsal; B, same, lateral; C, telson, dorsal; D, tooth on ventromesial carina of first article of antennular peduncle, lateral; E, third maxilliped, lateral; F, same, distal portion of antepenultimate article, and penultimate and ultimate articles, ventrolateral (setae omitted); G, second pereiopod, distal portion of merus, carpus and chela, lateral; H, third pereiopod, lateral; I, same, propodus and dactylus, lateral; J, same, dactylus, ventrolateral; K, fifth pereiopod, lateral; L, same, propodus and dactylus, lateral.

FIGURE 5. Alpheus djeddensis Coutière, 1897, male (cl 19.3 mm) from Farasan Islands, Saudi Arabia (FLMNH UF 36913); A, left (major) cheliped, carpus and chela, lateral; B, same, dactylus, lateral; C, right (minor) cheliped, lateral; D, same, mesial; E, same, distal portion of merus, carpus and chela with fingers open, lateral.

FIGURE 6. Alpheus djeddensis Coutière, 1897, male (cl 19.3 mm) from Farasan Islands, Saudi Arabia (FLMNH UF 36913); A, shrimp post-mortem (carapace damaged during collection), dorsal; B, same, lateral. Photographs by the author.

FIGURE 7. Alpheus djeddensis Coutière, 1897, male (cl indet.) from Thuwal, Saudi Arabia (specimen kept alive in RSRC); A, shrimp alive, dorsal; B, same, lateral. Photographs by the author.

FIGURE 8. Alpheus djeddensis Coutière, 1897, male (cl indet.) from Thuwal, Saudi Arabia (specimen kept alive in RSRC) [A–F]; major cheliped and third pereiopod (RSRC, used for DNA sequencing) [G]; A, frontal region, dorsal; B, tail fan, dorsal; C, left (major) chela, mesial, D, same, lateral; E, right (minor) cheliped and second pereiopod, lateral; F, right (minor) chela, lateral; G, major cheliped, mesial, and third pereiopod, lateral. Photographs by the author.

FIGURE 9. Alpheus djeddensis Coutière, 1897, female (cl indet.) from Thuwal, Saudi Arabia (specimen kept alive in RSRC); A, shrimp alive, dorsal; B, frontal region, dorsal; C, right (major) chela, mesial; D, left (minor) chela, distal portion of palm and fingers, mesial. Photographs by the author.

FIGURE 10. Alpheus djeddensis Coutière, 1897, in situ photographs; A, shrimp (ovigerous female) near burrow entrance, together with Cryptocentrus caeruleopunctatus (Rüppell) (goby not in frame and out focus), near Thuwal, Saudi Arabia; B, shrimp (sex unknown) outside of its burrow, together with C. caeruleopunctatus, southern Egypt. Photographs courtesy of Viktor Nunes Peinemann [A] and Ülar Tikk [B].

FIGURE 11. Alpheus shukran sp. nov., holotype, ovigerous female (cl 18.5 mm) from Masirah Island, Oman (FLMNH UF 71923); A, shrimp alive, dorsal; B, same, lateral. Photographs by the author.

FIGURE 12. Alpheus shukran sp. nov., holotype, ovigerous female (cl 18.5 mm) from Masirah Island, Oman (FLMNH UF 71923); A, frontal region, dorsal; B, tail fan, dorsal; C, left (major) chela, lateral; D, same, mesial; E, right (minor) chela, lateral; F, same, mesial; G, second pereiopod, lateral. Photographs by the author.

FIGURE 13. Alpheus shukran sp. nov., male (cl 11.0 mm) from Bandar Khayran, Oman (FLMNH UF 68873) [A–C]; ovigerous female (cl 13.2 mm) from the same locality (FLMNH UF 68870) [D–G]; A, shrimp alive, dorsal; B, same, lateral; C, frontal region, dorsal; D, shrimp alive, dorsal; E, same, lateral; F, carapace, frontal appendages and chelipeds, dorsal; G, frontal region, dorsal. Photographs by the author.

FIGURE 14. Alpheus shukran sp. nov., female (cl 12.7 mm) from Thuwal, Saudi Arabia (RSRC) [A–E]; aquarium-kept specimens (cl indet.) from Eilat, Israel [F, G]; male (cl 11.0 mm) from Bandar Khayran, Oman (FLMNH UF 68873) [H]; A, shrimp alive, dorsal; B, same, lateral; C, frontal region, dorsal; D, left (major) chela, mesial; E, right (minor) chela, mesial; F, shrimp alive, dorsal; G, shrimp in aquarium together with Cryptocentrus lutheri Klausewitz; H, male second pleopod, appendices masculina and interna, anterior. Photographs by the author [A–E] and Ilan Karplus [F, G, latter also published in Karplus et al. (1972a)].

FIGURE 15. Alpheus macellarius Chace, 1988, 1 male (cl 14.5 mm) from Raffles Lighthouse, Singapore (OUMNH.ZC.2014- 11-081); A, shrimp alive, dorsal; B, same lateral; C, frontal region, dorsal; D, tail fan, dorsal. Photographs by the author.

FIGURE 16. Alpheus macellarius Chace, 1988, female (cl 5.5 mm) from Nosy-Bé, Madagascar (FLMNH UF 14035) [A, B]; A, shrimp alive, dorsal; B, same, lateral. Alpheus cf. macellarius Chace, 1988, specimens from different western Pacific localities [C–H]; C, specimen (sex and cl indet.) from Koumac, New Caledonia (MNHN-IU-2018-778), shrimp alive, dorsal; B, same, lateral; E, female (cl 8.9 mm) from Madang, Papua New Guinea (MNHN-IU-2014-6031), shrimp alive, dorsal; F, same, lateral; G, ovigerous female (cl 10.2 mm) from Guam, Northern Mariana Islands (FLMNH UF 37357), shrimp alive, dorsal; H, same, lateral. Photographs by the author.

FIGURE 17. Alpheus macellarius Chace, 1988, in situ photographs; A, shrimp near burrow entrance, together with Cryptocentrus sp., Bali, Indonesia; B, shrimp and goby, Cryptocentrus caeruleomaculatus (Herre), outside of burrow, Bali, Indonesia; C, shrimp near its burrow among algae, partly exposed tide flat, Pulau Sekudu, Singapore; D, shrimp near burrow entrance, together with Cryptocentrus maudae Fowler, Sentosa, Singapore; E, F, shrimp (with bopyrid parasite) outside of burrow, together with Cryptocentrus cf. strigilliceps (Jordan & Seale), Watamu, Kenya. All identifications of shrimps and gobies tentative. Photographs courtesy of Andrey Ryanskiy (A, B), Marcus Ng (C, D), and Dawn Goebbels (E, F).

FIGURE 36. Further unknown, possibly undescribed species, presumably closely related to Alpheus djeddensis Coutière, 1897 and/or A. djiboutensis De Man, 1909, all from Indonesia; A, Alpheus sp. 1 with Ctenogobiops sp., Bali; B, Alpheus sp. 1 outside of burrow, Bali; C, Alpheus sp. 1 with Amblyeleotris sp., Triton Bay, West Papua; D, E, Alpheus sp. 2 outside of burrow, Bali; F, Alpheus sp. 3 (near A. tigrinus sp. nov.) with Amblyeleotris sp., Bali. Photographs courtesy of Andrey Ryanskiy [A, B, D, E], Karen Honeycutt [C], Yury Ivanov [F].

FIGURE 37. Further unknown, possibly undescribed species, presumably closely related to Alpheus djeddensis Coutière, 1897, from Singapore and Indonesia; A–C, Alpheus sp. 4 (banded, with deep blue antennular and antennal flagella), Tanah Merah, Singapore; D, Alpheus sp. 4, Changi, Singapore; E, Alpheus sp. 4, Beting Bronok, Singapore; F, Alpheus sp. 4, Bali, Indonesia; G, H, Alpheus sp. 5 (banded, with dark orange antennular and antennal flagella), Pulau Semakau, Singapore; I, Alpheus sp. 5, St. John’s Island, Singapore; J, Alpheus sp. 5, Bali, Indonesia. Photographs courtesy of Loh Kok Sheng [A–C, E], Marcus Ng [D, I], Andrey Ryanskiy [F, J], Ria Tan [G, H].

FIGURE 38. Examples of shrimp gobies associated with Alpheus spp. in the present study; A, Cryptocentrus caeruleopunctatus (Rüppell), Farasan Islands, Saudi Arabia, associated with A. djeddensis Coutière, 1897; B, Cryptocentrus cryptocentrus (Valenciennes), Masirah Island, Oman, associated with A. shukran sp. nov.; B, Cryptocentrus cf. leucostictus (Rüppell), Koumac, New Caledonia, associated with A. cf. macellarius Chace, 1988. Photographs by the author.