Armases roberti (H. Milne Edwards, 1853)

Guerao, Guillermo, Anger, Klaus & Schubart, Christoph D., 2007, Larvae and first-stage juveniles of the American genus Armases Abele, 1992 (Brachyura: Sesarmidae): a morphological description of two complete developments and one first zoeal stage, Journal of Natural History 41 (29 - 32), pp. 1811-1839 : 1814-1834

publication ID

https://doi.org/ 10.1080/00222930701500431

persistent identifier

https://treatment.plazi.org/id/930587AD-C054-FFB6-3952-FEA83AD269B2

treatment provided by

Felipe

scientific name

Armases roberti
status

 

Armases roberti View in CoL

( Figures 1–16 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 View Figure 10 View Figure 11 View Figure 12 View Figure 13 View Figure 14 View Figure 15 View Figure 16 )

Zoea I

Size. rdl50.85¡ 0.02 mm; cl50.52¡ 0.03 mm.

Carapace ( Figure 1a View Figure 1 ). Globose, smooth, with minute anterolateral protuberance. Dorsal spine present, well developed, strongly curved posteriorly. Rostral spine present, straight, similar in length to antennal protopod. Lateral spines absent. Pair of setae on posterodorsal and anterodorsal regions. Posterior and ventral margin without setae. Eyes sessile.

Antennule ( Figure 3a View Figure 3 ). Uniramous. Endopod absent. Exopod unsegmented with four terminal aesthetascs and one terminal seta.

Antenna ( Figure 4a View Figure 4 ). Similar in size to rostral spine. Protopodal process with two rows of unequal number of spines (8–11) of different sizes. Exopod elongated, with four terminal simple setae (one long, one medium-sized, and two minute). pl/el52.0–2.2.

Mandible. Palp absent; molar and incisor processes well developed.

Maxillule ( Figure 5a View Figure 5 ). Exopod and epipod setae absent. Coxal endite with six plumose setae. Basial endite with five setae (three cuspidate and two plumodenticulate) and with two teeth. Endopod two-segmented, with one seta on proximal segment, and one subterminal and four terminal plumodenticulate setae on the distal segment.

Maxilla ( Figure 7a View Figure 7 ). Coxal endite bilobed, with 5+3 plumodenticulate setae and with a marginal tooth on distal lobe (detail in Figure 7a View Figure 7 ). Basial endite bilobed with 5+4 plumodenticulate setae. Endopod unsegmented, bilobed, with 2+3 long plumodenticulate setae on inner and outer lobe, respectively. Scaphognathite (exopod) with four plumose marginal setae and long setose posterior process.

First maxilliped ( Figure 9a View Figure 9 ). Coxa with one sparsely plumose seta. Basis with 10 medial sparsely plumose setae arranged 2+2+3+3 on inner side, and a mat of long microtrichiae on outer proximal side. Endopod five-segmented, with 2, 2, 1, 2, 5 (one subterminal+four terminal) plumodenticulate setae. Exopod two-segmented; distal segment with four long plumose natatory setae.

Second maxilliped ( Figure 10a View Figure 10 ). Coxa without setae. Basis with four medial sparsely plumose setae arranged 1+1+1+1. Endopod three-segmented, with 0, 1, 6 setae. Exopod two-segmented; distal segment with four long plumose natatory setae.

Third maxilliped. Absent.

Pereiopods. Absent.

Abdomen ( Figures 14a View Figure 14 , 15a View Figure 15 ). Five somites. Somites 2 and 3 with a pair of dorsolateral processes. Somites 3–5 with posterolateral pocesses. Somites 2–5 with a pair of posterodorsal simple setae.

Pleopods. Absent.

Telson ( Figures 14a, e View Figure 14 , 15a, e View Figure 15 ). Bifurcate, furca large, slightly divergent with three pairs of serrulate setae on posterior margin. A minute scale-like spine on outer margin and two arrow-shaped small spines on dorsal margins of furcal arms. fl/bt51.5–1.7.

Zoea II

Size. rdl51.12¡ 0.04 mm; cl50.72¡ 0.02 mm. Carapace ( Figure 1b View Figure 1 ). Two pairs of anterodorsal setae. Each lateroventral margin with two setae (one sparsely plumose+one pappose). Eyes stalked. Otherwise unchanged.

Antennule ( Figure 3b View Figure 3 ). Unchanged.

Antenna ( Figure 4b View Figure 4 ). Endopod bud present. pl/el52.2–2.4. Otherwise unchanged.

Mandible. Unchanged.

Maxillule ( Figure 5b View Figure 5 ). Basial endite with seven plumose setae. Exopod plumose seta present. Otherwise unchanged.

Maxilla ( Figure 7b View Figure 7 ). Scaphognathite with eight (3+5) plumose marginal setae. Otherwise unchanged.

First maxilliped. Exopod distal segment with six long plumose natatory setae. Otherwise unchanged.

Second maxilliped. Exopod distal segment with six long plumose natatory setae. Otherwise unchanged.

Third maxilliped. Present as undifferentiated buds.

Pereiopods. Present as undifferentiated buds.

Abdomen ( Figures 14b View Figure 14 , 15b View Figure 15 ). First somite with one mid-dorsal seta. Otherwise unchanged.

Telson ( Figure 14b View Figure 14 , 15b View Figure 15 ). fl/bt51.6–1.7. Otherwise unchanged.

Zoea III

Size. rdl51.45¡ 0.04 mm; cl50.85¡ 0.03 mm.

Carapace ( Figure 1c View Figure 1 ). Four pairs of anterodorsal setae. One pair of setae near to the base of the dorsal spine. Each ventral margin with five setae (two sparsely setose+three pappose). Otherwise unchanged.

Antennule ( Figure 3c View Figure 3 ). Exopod with four terminal aesthetascs and one minute terminal seta. Otherwise unchanged.

Antenna ( Figure 4c View Figure 4 ). Endopod bud elongated, as long as exopod or slightly longer (without setae). pl/el52.6–2.9. Otherwise unchanged.

Mandible. Unchanged.

Maxillule ( Figure 5c View Figure 5 ). Epipod seta present. Basial endite with eight setae. Otherwise unchanged.

Maxilla ( Figure 7c View Figure 7 ). Basial endite with 5+5 setae. Scaphognathite with 12–13 plumose marginal setae. Otherwise unchanged.

First maxilliped ( Figure 9b View Figure 9 ). Endopod segments 2 and 3 with one additional seta. Exopod distal segment with eight long plumose natatory setae. Otherwise unchanged.

Second maxilliped. Exopod distal segment with eight long plumose natatory setae. Otherwise unchanged.

Third maxilliped. Biramous, unsegmented.

Pereiopods ( Figure 12a View Figure 12 ). Pereiopods unsegmented. Chelipeds bilobed.

Abdomen ( Figures 14c View Figure 14 , 15c View Figure 15 ). Somite six present, without setae. Pleopod buds present on somites 2–5, endopods absent. Otherwise unchanged.

Telson ( Figures 14c View Figure 14 , 15c View Figure 15 ). fl/bt52.4–2.6. Otherwise unchanged.

Zoea IV

Size. rdl51.50¡ 0.07 mm; cl50.97¡ 0.05 mm. Carapace ( Figure 1d View Figure 1 ). Five pairs of anterodorsal setae. Each ventral margin with seven to eight (four to five sparsely plumose+three pappose) setae. Otherwise unchanged.

Antennule ( Figure 3d View Figure 3 ). Exopod with one basal seta, and three subterminal and four terminal aesthetascs.

Antenna ( Figure 4d View Figure 4 ). Endopod two-segmented, longer, reaching middle of the length of spinous process. Exopod without minute setae. pl/el52.7–2.9.

Maxillule ( Figure 5d View Figure 5 ). Coxal endite with seven setae. Basial endite with 11 setae. Otherwise unchanged.

Maxilla ( Figure 7d View Figure 7 ). Coxal endite with 7+4–5 setae. Basial endite with 7+5–6 setae. Scaphognathite with 18–21 marginal plumose setae. Otherwise unchanged.

First maxilliped ( Figure 9c View Figure 9 ). Coxa with two setae. Fifth segment of endopod with additional subterminal seta. Exopod distal segment with nine long plumose natatory setae. Otherwise unchanged.

Second maxilliped ( Figure 10b View Figure 10 ). Exopod distal segment with 10 long plumose natatory setae. Otherwise unchanged.

Third maxilliped. Epipod now present, rudimentary.

Pereiopods ( Figure 12b View Figure 12 ). Chelipeds and pereiopods 2–5 slightly segmented.

Abdomen ( Figures 14d View Figure 14 , 15d View Figure 15 ). First somite with three long mid-dorsal setae. Pleopod buds elongated, endopod buds present. Otherwise unchanged.

Telson ( Figures 14d View Figure 14 , 15d View Figure 15 ). fl/bt52.2–2.4. Otherwise unchanged.

Megalopa

Size. cl51.18¡ 0.08 mm; cw50.85¡ 0.07 mm.

Carapace ( Figure 2a, b View Figure 2 ). Longer than broad. Rostrum ventrally deflected with median cleft, and with longitudinal medial carina and lateral prominent undulations.

Antennule ( Figure 3d View Figure 3 ). Peduncle three-segmented, with 3, 1, 1 setae, respectively. Endopod absent. Exopod three-segmented, with 0, 6, 3 aesthetascs and 0, 2, 2 setae, respectively.

Antenna ( Figure 4d View Figure 4 ). Peduncle three-segmented, with 0, 1, 1 setae, respectively. Flagellum six-segmented, with 0, 2–3, 1, 5, 1, 3 setae, respectively.

Mandible ( Figure 4g View Figure 4 ). Palp two-segmented, with four setae on distal segment.

Maxillule ( Figure 6a View Figure 6 ). Coxal endite with 11–12 setae. Basial endite with 16(15+1)– 18(16+2) setae. Endopod unsegmented, with two proximal and four distal setae.

Maxilla ( Figure 8a View Figure 8 ). Coxal endite bilobed, with 12+5 setae. Basial endite bilobed with 7+7 setae. Endopod unsegmented, with one subterminal seta, or none. Scaphognathite with 36–39 plumose marginal setae and two anterior and one posterior lateral setae.

First maxilliped ( Figure 9d View Figure 9 ). Epipod with seven long setae. Coxal endite with six setae. Basial endite with 11 setae. Endopod with five setae. Exopod two-segmented, proximal segment with three distal plumose setae, distal segment with three to four long terminal plumose setae.

Second maxilliped ( Figure 10c View Figure 10 ). Epipod rudimentary. Coxa and basis not differentiated, without seta. Endopod four-segmented with 0, 1, 3, 6–7 setae, respectively. Exopod twosegmented, proximal segment with one seta, distal segment with five terminal plumose setae.

Third maxilliped ( Figure 11a View Figure 11 ). Epipod elongated with 15 long setae. Coxa and basis not differentiated, with nine setae. Endopod five-segmented, with 8–9, 8, 3–4, 4, 7 setae, respectively. Exopod two-segmented, proximal segment with one seta and distal segment with four long terminal plumose natatory setae.

Pereiopods ( Figure 13c–i View Figure 13 ). All articles well differentiated. Pereiopods 3 and 4 with one coxal process each. Dactylus of fifth pereiopod with three long terminal setae and one short terminal spine.

Sternum ( Figure 13a View Figure 13 ). Maxillipeds and cheliped sternites fused with eight setae. All sternal sutures interrupted medially.

Abdomen ( Figure 16a, b View Figure 16 ). Six somites present. Somites 1–6 with 7, 12, 14, 16, 14, 4 setae, respectively. Somites 2–5 each with a pair of biramous pleopods.

Pleopods ( Figure 16e–h View Figure 16 ). Endopod unsegmented, with two terminal hooks, exopod unsegmented with 14–15, 13–15, 13–14, 11–12 long marginal plumose natatory setae, respectively.

Uropods ( Figure 16i View Figure 16 ). Two-segmented on somite 6, proximal segment with one, and distal segment with seven long plumose setae, respectively.

Telson ( Figure 16a, c, d View Figure 16 ). Posterior margin rounded, with one or two plumose setae. Dorsal surface with six setae and with two ventral setae.

First juvenile

Size. cl51.35¡ 0.02 mm; cw51.17¡ 0.02 mm.

Carapace ( Figure 2c View Figure 2 ). Longer than broad, quadrangular. Frontal region broad measuring one half of carapace width. Anterolateral margins with three teeth, first largest and third smallest.

Antennule ( Figure 3f View Figure 3 ). Peduncle three-segmented, with 6, 1, 1 setae, respectively. Endopod absent. Exopod two-segmented, with 0, 3–4 aesthetascs, respectively, and 0, 2–3 setae.

Antenna ( Figure 4f View Figure 4 ). Peduncle three-segmented, with 2, 1, 1 setae, respectively. Usually, flagellum five-segmented, with 0, 2, 1, 4, 3 setae, respectively.

Mandible. Palp two-segmented, with five setae on distal segment.

Maxillule ( Figure 6b View Figure 6 ). Coxal endite with 14 setae. Basial endite with 19–20 setae. Endopod unsegmented, with two proximal and three distal setae.

Maxilla ( Figure 8b View Figure 8 ). Coxal endite bilobed with 13+5 setae. Basial endite bilobed with 9+8 setae. Endopod unsegmented, without setae. Scaphognathite with 48 plumose marginal setae and eight lateral setae.

First maxilliped ( Figure 9e View Figure 9 ). Epipod with 11 long setae. Coxal endite with 12 setae. Basial endite with 20–21 setae. Endopod with five setae. Exopod two-segmented, proximal segment with zero to two setae, distal segment with four long terminal plumose setae.

Second maxilliped ( Figure 10d View Figure 10 ). Coxa and basis undifferentiated, without setae. Endopod four-segmented with 2, 1, 5, 9 setae, respectively. Exopod two-segmented, proximal segment with eight setae and distal segment with five terminal plumose setae.

Third maxilliped ( Figure 11b View Figure 11 ). Epipod elongated with 20 long setae. Coxa and basis undifferentiated with 18–21 setae. Endopod five-segmented with 20, 16, 6–7, 5, 5 setae, respectively. Exopod two-segmented, proximal segment with eight setae and distal segment with five long terminal plumose setae.

Pereiopods ( Figure 13c–j View Figure 13 ). Pereiopods 3 and 4 without coxal processes. Dactylus of fifth pereiopod without long terminal setae.

Abdomen. Six somites present with pleopods reduced, without setae.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Sesarmidae

Genus

Armases

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