Synalpheus brooksi Coutière, 1909

Macdonald, Kenneth S. & Duffy, J. Emmett, 2006, Two New Species of Sponge-Dwelling Snapping Shrimp from the Belizean Barrier Reef, with a Synopsis of the Synalpheus brooksi Species Complex, American Museum Novitates 3543, pp. 1-22 : 18-20

Synalpheus brooksi Coutière, 1909

figure 16

Synonymies [per Dardeau, 1984].

MATERIAL EXAMINED: ³(VIMS 88SB5705), Aguadargana Reef , San Blas Islands, Panama, from the canals of Agelas clathrodes . ♀ , 2 ³

Fig. 16. Synalpheus brooksi . ³ 3.47 mm (VIMS 88SB5705) from Agelas clathrodes, Aguadargana Reef, San Blas Islands , Panama: A, anterior region of carapace and cephalic appendages, dorsal view; B, telson, dorsal view; C, anterior region of chela of major first pereopod, lateral view. ♀ 3.93 mm (VIMS 01LS0214) from Spheciospongia sp. , Shark Rock, Exuma Islands, Bahamas: D, anterior region of carapace and cephalic appendages, dorsal view; E, telson, dorsal view; F, anterior region of chela of major first pereopod, lateral view. ³ 3.40 mm (VIMS 05CBC0220) from Lissodendoryx colombiensis, Blue Ground Range , Belize: G, anterior region of carapace and cephalic appendages, dorsal view; H, anterior region of chela of major first pereopod, lateral view. ³ 2.82 mm (VIMS 05CBC0221) from L. colombiensis, Blue Ground Range , Belize; I, telson, dorsal view. Scale bar 5 1 mm.

(VIMS 93P2104-06), Limones Reef, San Blas Islands, Panama, from the canals of Lissodendoryx colombiensis . ♀, ³ (VIMS 01LS0212, 0214), Shark Rock, Exuma Islands, Bahamas, from the canals of Spheciospongia sp. ♀, 8 ³ (VIMS 98CBC0802-10), Sand Bores, Belize, from the canals of Hyatella intestinalis . 3 ³ (VIMS 01LS1001, 1103-04), Shark Rock, Exuma Islands, Bahamas, from the canals of Hyatella sp. 2 ³ (VIMS 05CBC0220-21), Blue Ground Range, Belize, from the canals of L. colombiensis .

COLOR IN LIFE: Nondescript. Body transparent, with distal palm and fingers of major chela orange. Ovaries and developing embryos pale, ranging from green to gray to pink.

HOSTS AND ECOLOGY: Synalpheus brooksi occurs predominantly in two common shallow-water sponges, Spheciospongia vesparium and Lissodendoryx colombiensis . Individuals are also found occasionally in other shrimpbearing sponge species (personal obs.; Macdonald et al., 2005). They are typically found in dense congregations of 10 s to 1000 s of individuals ( Pearse, 1932, 1950; Dardeau, 1984), often with somewhat skewed sex ratios (personal obs.; Duffy 1996a), for example, 10– 20 male /juvenile shrimp per mature female.

DISTRIBUTION: Western Atlantic; Gulf of Mexico; Brazil.

REMARKS: Synalpheus brooksi is one of the most commonly collected species in the Gambarelloides group, mostly due to its wide geographic range and its presence in the common and easily collected loggerhead sponge, S. vesparium . Synalpheus brooksi is easily distinguishable from all other described species of this complex by the shape of the superior marginal protuberance of the major chela, which is bluntly conical and directed upward and slightly away from the palm.