Alpheus formosus Gibbes 1850
Creators: name: Pasinatto, Karmine
name: Mantelatto, Fernando L.
name: Terossi, Mariana
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Alpheidae
Alpheus
Alpheus formosus

description: Alpheus formosus Gibbes, 1850
Zoea I Carapace length: 0.42 ± 0.04 mm (n = 10 larvae)
Cephalothorax (Fig. 1A, 1B): rostrum absent; pterygostomian spine present; eyes sessile.
Antennule (Fig. 1C): peduncle 3-segmented; endopod as a plumose seta; exopod with 4 terminal aesthetascs (2 spatulate, one of them being more robust) and 1 terminal plumose seta.
Antenna (Fig. 1D): peduncle 2-segmented with 1 medial distal spiniform projection near the endopod; endopod with 1 terminal plumose seta and 1 medial distal spiniform projection; exopod (scaphocerite) 8-segmented with 11 plumose setae (2, 1, 2, 1, 1, 1, 1, 2), distal segment with 1 simple seta.
Mandible: palp absent.
Maxillule (Fig. 1E): coxa with 6 (1 medial simple, 3 terminal simple, one larger in proximal region, 1 terminal serrulate plumose, 1 lateral simple) setae; base with 2 spiniform projections and 1 lateral simple seta; endopod with 1 terminal plumoserrulate and 1 lateral simple setae; exopod absent.
Maxilla (Fig. 1F): coxa with 2 medial simple setae; base bilobed, each lobe with 5 medial simple setae (distal seta longer); endopod with 1 medial proximal simple and 2 terminal long (1 simple and 1 plumose) setae, with microtrichia; exopod (scaphognathite) with 5 plumose setae, without microtrichia.
First maxilliped (Fig. 1G): coxa with 1 medial distal simple seta; base with 7 medial simple setae arranged 2+2+2+1; endopod 2-segmented with 1 medial distal simple seta, 5 [4 simple (1 medial + 3 terminal) and 1 terminal serrulate] setae; exopod 4-segmented with 0, 0, 2, 2 terminal natatory plumose setae plus 1 lateral distal simple seta on second segment.
Second maxilliped (Fig. 1H): coxa without setae; base with 4 medial simple setae arranged 1+1+1+1; endopod 4-segmented with 1 medial distal simple, 0, 1 medial distal serrulate, 5 (1 medial simple, 3 lateral simple and 1 terminal serrulate) setae; exopod 4-segmented with 0, 1, 2, 2 terminal natatory plumose setae plus 1 terminal simple seta on second segment.
Third maxilliped (Fig. 1I): coxa with 1 medial distal simple seta; base with 2 medial simple setae arranged 1+1; endopod 5-segmented with 0, 1 medial, 0, 3 (2 lateral proximal and 1 medial distal), 3 (2 medial proximal and 1 terminal) simple setae; exopod 5-segmented with 0, 0, 2, 2, 2 terminal natatory plumose setae plus 1 medial simple seta on second segment.
Pereopod (Fig. 1J): first as a biramous bud.
Pleon (Fig. 1A, 1K,): with 5 somites, presence of simple dorsal setae on the somites (Figs. 1L, 3B, 3C); lateral spines absent; pleopods absent; anal spine present (Fig. 1M).
Telson (Fig. 1M): triangular, with 7+7 (5 inners plumose, 2 outers plumose laterally) setae, 4 inner setae with shorter setules in the proximal region, inner pair shorter; 6 inner pairs with a row of denticles in the distal margin, 4 innermost pairs with marginal spines (Fig. 3G, 3H).
description: Published as part of Pasinatto, Karmine, Mantelatto, Fernando L. & Terossi, Mariana, 2020, First zoeal stage of the snapping shrimps Alpheus formosus Gibbes, 1850 and Alpheus malleator Dana, 1852 (Caridea: Alpheidae), with new characters to the genus, pp. 540-550 in Zootaxa 4820 (3) on pages 541-542, DOI: 10.11646/zootaxa.4820.3.7, http://zenodo.org/record/4441079