Portunus spinimanus, (Latreille, 1819)

Mantelatto, Fernando L., Pantaleão, João A. F., Cuesta, José A., Fransozo, Adilson & Felder, Darryl L., 2018, The first zoeal stage morphology of Achelous spinimanus (Latreille), A. gibbesii (Stimpson), and Portunus sayi (Gibbes) (Decapoda, Brachyura) provides support for molecular phylogeny, Zootaxa 4378 (1), pp. 71-84 : 73-76

Achelous spinimanus (Latreille, 1819)

( Figs. 1a–f ; 2a–e )

Description of zoea I. Dimensions: CL: 0.43 ± 0.0 2 mm; CW: 0.37 ± 0.0 1 mm; DL: 0.54 ± 0.0 2 mm; RL: 0.28 ± 0.0 2 mm; RDL: 1.19 ± 0.0 4 mm; DL/RL: 1.96 ± 0. 20 (n = 10).

Cephalothorax ( Figs. 1a, b ): dorsal spine long, curved distally backward and without setae. Rostral spine long, slightly shorter than antennal protopod. Lateral spines well developed. One pair of posterodorsal simple setae present, anterodorsal setae absent; lateroventral margins with ten or 11 denticles and without setae. Eyes sessile.

Antennule ( Figs. 1a, c ): uniramous, smooth. Primary flagellum with two long terminal aesthetascs and two simple setae; accessory flagellum absent.

Antenna ( Figs. 1a, d ): uniramous, protopod well developed and long, with two rows of 12–16 spines along most of protopod length except the base and increasing in size toward tip, in midpart a group of seven small spinules. Endopod absent. Exopod unsegmented, approximately one-fourth (1/4) of protopod length, with two unequal terminal simple setae, longest one slightly longer than exopod length.

Mandibles (not illustrated): incisor, molar process developed. Palp absent.

Maxillule ( Fig. 1e ): coxal endite with one simple, five plumodenticulate setae. Basial endite with two cuspidate, three plumodenticulate setae, microtrichia on proximal margin. Endopod 2-segmented, proximal segment without setae; distal segment with six (two medial, two subterminal and two terminal) sparsely plumodenticulate setae. Exopod and epipod setae absent.

Maxilla ( Fig. 1f ): Coxal endite bilobed, with three plumose setae on each lobe, distal lobe with one terminal small spine. Basial endite bilobed, with four plumodenticulate setae on both lobes, proximal lobe with one terminal spine. Unsegmented endopod bilobed, with two (one long sparsely plumodenticulate, one shorter simple) setae on proximal lobe, and four (one long sparsely plumodenticulate, three shorter simple) setae on distal lobe. Exopod (scaphognathite) margin with four plumose setae and long distal process. Microtrichia on both proximal and distal margins of coxal endite, basial endite, endopod and distal process of scaphognathite.

First maxilliped ( Fig. 2a ): coxa without setae. Basis with ten simple setae arranged 2+2+3+3. Endopod 5- segmented with two (sparsely plumose), two (sparsely plumose), zero, two (one sparsely plumose, one sparsely plumodenticulate), and five (one subterminal simple, one terminal plumodenticulate) setae, respectively. Exopod 2-segmented, distal segment with four long terminal plumose natatory setae.

Second maxilliped ( Fig. 2b ): coxa without setae. Basis with four simple setae arranged 1+1+1+1. Endopod 3- segmented, with one sparsely plumose, one sparsely plumose, five (three simple, one serrulate, one long sparsely plumose) setae, respectively. Exopod 2-segmented, distal segment with four long terminal plumose natatory setae.

Third maxilliped: absent.

Pereiopods: absent.

Pleon ( Figs. 2c, d ): five pleonites present. Pleonite one without setae, pleonites 2–5 with one pair of posterodorsal simple setae. Pleonites 2, 3 with one pair of dorsolateral processes. Pleonites 3–5 with long and acute posterolateral processes. Pleopods absent.

Telson ( Fig. 2c–e ): furcated. Furcae distally spinulated, with one pair of well-developed lateral spines, one pair of small lateral spines just below the long ones, one pair of dorsal spines; inner margin with three pairs of serrulate setae.

Figures

FIGURE 2. Achelous spinimanus (Latreille, 1819), Zoea I. a. First maxilliped; b. Second maxilliped; c. Pleon, dorsal view; d. Pleon, lateral view; e. detail of spinulation of the telson furcae.(Scale bars:a, b = 0.05 mm; c, d = 0.1mm; e = 0.02 mm)

FIGURE1. Achelous spinimanus (Latreille, 1819), ZoeaI. a.Cephalothorax,lateral view; b. Magnification of thelateroventral margin of cephalothorax; c. Antennule; d. Antenna; e. Maxillule; f.Maxilla. (Scale bars: a = 0.1 mm; b - f = 0.05 mm)