Munidopsis expansa Benedict, 1902

Rodríguez-Flores, Paula C., Bracken-Grissom, Heather D., Lemaitre, Rafael, Felder, Darryl L. & Nizinski, Martha S., 2025, A new squat lobster (Crustacea, Decapoda, Munidopsidae) from the western Atlantic with redescription of Munidopsis expansa Benedict, 1902 and several range extensions, ZooKeys 1248, pp. 321-340 : 321-340

publication ID

https://doi.org/10.3897/zookeys.1248.156346

publication LSID

lsid:zoobank.org:pub:B0D76E95-B0DC-4D15-8F05-E9244949E19F

DOI

https://doi.org/10.5281/zenodo.16780610

persistent identifier

https://treatment.plazi.org/id/50C8FCA4-43B5-5458-8D43-783FC14EF903

treatment provided by

ZooKeys by Pensoft

scientific name

Munidopsis expansa Benedict, 1902
status

 

Munidopsis expansa Benedict, 1902 View in CoL

Figs 1 View Figure 1 , 5 A – H View Figure 5 , 6 A – C View Figure 6 , 7 A, B View Figure 7

Munidopsis expansa Benedict, 1902: 282, fig. 26 (type locality: off Florida, 770 m). — Chace 1942: 81. — Pequegnat and Pequegnat 1970: 147 (no record). — Pequegnat and Pequegnat 1971: 19. — Baba et al. 2008: 141 (compilation). — Felder et al. 2009: 1066 (compilation). View in CoL

Material examined.

Holotype. • North Atlantic Ocean, United States, off Florida, Daytona Beach , 29.65, 79.8167, 770 m, 4 May 1886: ov. F 21.0 mm ( USNM 20561 About USNM ).

Other material.

West Florida Slope, USGS-LOPH II -ROV-2010-CH-008 , 26.207882, - 84.725818, 508– 492 m, 29 September 2010: 1 M 16.0 mm ( USNM 1194614 About USNM , GenBank Accession No. PV 297962 ) GoogleMaps , USGS-LOPH II -CH-2010-081 , 26.213611, - 84.725486, 525 m, 30 September 2010: 1 F 17.1 mm ( USNM 1194615 About USNM , GenBank Accession No. PV 297961 ) GoogleMaps . • North Atlantic Ocean, Gulf of Mexico, United States, R/V OREGON II, Station 11140 , 24.25, - 87.73, 503 m, 10 August 1970: not measured ( USNM 1662589 About USNM ) . • North Atlantic Ocean, Florida Straits / Gulf of Mexico, Cuba, off Havana, RV Atlantis, Harvard-Havana Expedition, 23.0750000, 82.616666, 603.5 m, 23 March 1939: 1 F 17.7 mm ( MCZ CRU 11732 ) GoogleMaps . • Belize, East of Stann Creek , 16.97, - 87.88, 457–732 m, 10 June 1962: 1 F 19.0 mm ( USNM 268733 About USNM ) .

Diagnosis.

Carapace dorsally covered with scales, shorter and more abundant on gastric region, wider scales posteriorly; cervical grooves distinct (Fig. 6 A – C View Figure 6 ). Rostrum moderately broad, dorsally elevated and with median carina, distally trifid. Frontal margin slightly concave behind ocular peduncle. Orbit slightly excavated, outer orbital angle with small blunt lobe. Anterolateral angle armed with broad spine. Branchial margin armed with 3 broad spines. Abdominal tergites unarmed. Telson divided into 8 plates. Sternite 3 anterolaterally rounded, anterior margin with median lobe flanked by 2 lobes, sternite 4 broadly subtriangular. Eyes unarmed, movable, epistomial spine present, cornea globular, elongated. Article 1 of antennule with dorsolateral and distolateral spines. Article 1 of antenna with strong distomesial spine and distolateral spines. Mxp 3 merus serrated but without distinct spines on flexor margin, extensor margin with short spine. P 1 stout, length less than twice PCL; meri armed with distal spines; carpi, palm and fingers unarmed; fixed finger without denticulate carina on distolateral margin; dactylus dorsally carinate. P 2–4 stout; meri carinate on dorsal margin; dactyli slender, distally curving, flexor margin with 11–12 teeth decreasing proximally along entire length. Epipods present on P 1 and 2.

Redescription.

Carapace: Slightly broader than long, widest at midlength; moderately convex from side to side. Dorsal surface densely covered with scales, most abundant on gastric region, each scale marginally with short setae; hepatic and anterior branchial regions with scales and some granules; posterior cardiac and intestinal region covered with larger scales. Regions well delineated by deep furrows including distinct anterior and posterior cervical grooves. Gastric region slightly elevated. Cardiac region divided by a transverse furrow in anterior and posterior cardiac regions. Posterior margin unarmed, preceded by elevated ridge. Rostrum moderately broad, dorsally elevated, with median carina, width 0.2–0.3 × anterior width of carapace, directed strongly upwards, distally trifid, with strong median spine twice as long as broad lateral spines (Fig. 5 A View Figure 5 ), 0.4 × PCL, 1.3–1.8 × as long as broad. Frontal margin slightly concave behind ocular peduncle; blunt outer orbital angle above antennal peduncle, sometimes armed with 1 or 2 minute spines (absent in the holotype); spine below antennal proximal mesial angle, ventral to frontal margin, close to epistomial region. Lateral margins slightly convex, converging posteriorly; anterolateral spine broad; anterior branchial margin with 2 broad spines; 1 broad branchial spine just behind posterior branch of cervical groove. Pterygostomian flap surface covered with granules and scales, anteriorly rounded.

Sternum: 0.9 × as long as broad, maximum width at sternite 7. Sternite 3 broad, 1.5 × wider than long, anterolaterally rounded, anterior margin with median lobe flanked by 2 rounded lobes. Sternite 4 narrowly elongated anteriorly; surface depressed in midline, with scattered scales; greatest width 2.3 × that of sternite 3; 2 × wider than long.

Pleon: Unarmed; tergites 2–4 each with 2 elevated transverse ridges, lateral part of dorsal surface covered with granules and scales; tergites 5 and 6 with anterior ridge only; tergite 6 with weakly produced posterolateral lobes and nearly transverse posteromedian margin. Telson composed of 8 plates; 1.4–1.5 × as wide as long.

Eye: Eyestalk movable, partially concealed by rostrum; peduncle covered with few granules; cornea elongated, longer than peduncle, ovoid; lateral surface contiguous to epistomial spine, epistomial spine ventral to frontal margin.

Antennule: Article 1 of peduncle with subequal dorsolateral and distolateral spines, dorsolateral spine slenderer; distomesial margin slightly produced, granulated.

Antenna: Peduncle slightly exceeding eye. Article 1 with strong distomesial and distolateral spines, not reaching distal margin of article 2, distolateral spines shorter. Article 2 with well-developed distolateral spine, distomesial margin produced, granulated. Articles 3 and 4 unarmed.

Mxp 3: Lateral surface with granules. Ischium as long as merus measured on extensor margin. Merus serrated, but without distinct spines on flexor margin; extensor margin weakly serrated, with small distal spine.

P 1: Stout, with numerous minute granules and scales, each scale marginally with few short setae; 1.2–1.6 × PCL. Merus 2.6 × carpus length, with 4 distal spines. Carpus 0.7–0.9 × longer than broad, unarmed, with few granules on dorsal and lateral surfaces. Palm unarmed, stout, 2 × carpus length, 1.2 × longer than broad. Fingers unarmed, 1.2 × longer than palm, opposing margins nearly straight, not gaping, spooned; fixed finger without denticulate carina on distolateral margin, mobile finger with dorsal carina.

P 2–4: Stout, coarsely granulated, devoid of setae, cylindrical in cross-section, slightly decreasing in size posteriorly. P 2 merus stout, not surpassing P 1 length, 0.6 × PCL, 3.5 × longer than high, 1.1 × length of P 2 propodus. P 2–4 meri decreasing in length posteriorly (P 3 merus 0.9 × length of P 2 merus, P 4 merus 0.85 × length of P 3 merus); extensor margin carinate, with small granules along entire length, distally flattish, ending in thick spine; flexor margin granulated. P 2–4 carpi with thick distal spine on extensor margin, lateral surface with granulated carina. P 2–4 propodi 3.5–5 × as long as high, triangular in cross-section, unarmed. P 2–4 dactyli 0.5–0.6 × length of propodi; distal claw short, flexor margin nearly straight, with 11 or 12 dactylar teeth on entire length, each tooth with slender corneous spine, ultimate tooth closer to penultimate tooth than to dactylar angle.

Epipods: Present on P 1 and 2.

Coloration: Bright orange. Distal parts of articles, rostrum and tips of spines whitish (Fig. 7 A, B View Figure 7 ).

Ecology.

Specimens collected on the West Florida Slope, at station USGS-LOPH II - ROV- 2010 - CH- 008 were observed walking on dead coral rubble of Desmophyllum pertusum . In general, the habitat was characterized by large, mostly dead colonies of D. pertusum usually found on the edge of outcrops. Smaller live colonies of D. pertusum , Plummerella sp. , as well as other octocoral species and hexactinellid sponges, were found scattered over dead, consolidated coral rubble.

Remarks.

Munidopsis expansa was initially described by Benedict (1902) from material collected off Florida. This species belongs to a group of species characterized by a trifid and elevated rostrum, unarmed carapace and abdomen, 8–10 telson plates, stout P 1 (less than twice PCL), stout P 2–4 and epipods on P 1 and 2. In addition to M. expansa from the western Atlantic, this group of species includes M. testuda Rodríguez-Flores, Seid, Rouse & Giribet, 2023 , known only from the Galapagos Islands of the eastern Pacific, and the new species described herein. Differences among these species are discussed under the Remarks of the new species.

Distribution.

North coast of Cuba, Gulf of Mexico, Atlantic coast of Florida; 457–1107 m.

MCZ

Museum of Comparative Zoology

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

InfraOrder

Anomura

SuperFamily

Galatheoidea

Family

Munidopsidae

Genus

Munidopsis

Loc

Munidopsis expansa Benedict, 1902

Rodríguez-Flores, Paula C., Bracken-Grissom, Heather D., Lemaitre, Rafael, Felder, Darryl L. & Nizinski, Martha S. 2025
2025
Loc

Munidopsis expansa

Felder DL & Álvarez F & Goy JW & Lemaitre R 2009: 1066
Baba K & Macpherson E & Poore G & Ahyong S & Bermudez A & Cabezas P & Lin C-W & Nizinski M & Rodrigues C & Schnabel K 2008: 141
Pequegnat WE & Pequegnat LH 1971: 19
Pequegnat LH & Pequegnat WE 1970: 147
Chace FA 1942: 81
Benedict JE 1902: 282
1902