Mesanthura estacahuitensis, Jarquín-Martínez & García-Madrigal, 2021

Jarquín-Martínez, Ubaldo & García-Madrigal, María del Socorro, 2021, Six new species of Anthuridae (Peracarida: Isopoda) from the southern Mexican Pacific, European Journal of Taxonomy 760 (1), pp. 61-100 : 79-82

publication ID

https://doi.org/ 10.5852/ejt.2021.760.1441

publication LSID

lsid:zoobank.org:pub:666AD5F1-6AC4-4940-B05C-4B57C3063593

DOI

https://doi.org/10.5281/zenodo.5121778

persistent identifier

https://treatment.plazi.org/id/8C5D87D5-BA5D-FFBC-FDE4-912CFE6448A1

treatment provided by

Felipe

scientific name

Mesanthura estacahuitensis
status

sp. nov.

Mesanthura estacahuitensis View in CoL sp. nov.

urn:lsid:zoobank.org:act:5B34AF3F-DB2A-4B58-9956-32F0361CD6C4

Figs 11–13 View Fig View Fig View Fig , 20D View Fig , Table 1 View Table 1

Etymology

This species is named after its type locality, Estacahuite Beach, Oaxaca.

Material examined

Holotype MEXICO • ♀ (body length 6.8 mm); Oaxaca, Puerto Ángel, Estacahuite Beach ; 15°40′ N, 96°29′ W; depth 2–4 m; 10 Sep. 2005; J.R. Bastida-Zavala et al. leg.; coral rock; UMAR-PERA 547 . GoogleMaps

Description

Holotype (♀, UMAR-PERA 547)

BODY ( Figs 11A View Fig , 20D View Fig ). Length 6.8 mm, 11.1 times as long as wide, strongly pigmented; cephalon almost as wide as long, circular eyes, in lateral position, rostrum slightly shorter than lateral angles; body proportion: C<1=2>3<4=5>6>7. Pereonites 2–3 cylindrical, 4–6 rectangular, pereonite 7 square; pleonites 1–5 fused, slightly wider than long, 0.9 times as long as pereonite 7, pleonite 6 free with a medial incision on the distal margin; telson linguiform, medially wider, 1.8 times as long as wide, apex broadly rounded with three pairs of long smooth setae and one pair of short plumose setae; one pair of proximal statocysts.

ANTENNULE ( Fig. 11B View Fig ). Peduncle with three articles; article 1 sub-equal in length to articles 2 and 3 together with plumose sensory setae; article 2 sub-square with distal plumose sensory setae; article 3 rectangular, 2.1 times as long as wide; flagellum with three articles, article 1 tiny with one plumose sensory seta; article 2 longest, 0.6 times as long as last peduncle article; article 3 with four aesthetascs and three long simple setae.

ANTENNA ( Fig. 11C View Fig ). Peduncle with five articles; articles 2–5 with grooved external margin, article 2 sub-square; article 3 shorter than the others; article 4 square; last article 1.3 times as long as article 4 with a group of apical setae; flagellum 0.6 times as long as last peduncle article with four articles decreasing distally and with numerous fine setae.

MAXILLIPED ( Fig. 11D View Fig ). Palp with three articles. Article 1 rectangular, 1.3 times as wide as long with a long seta in the internal distal angle; article 2 with two setae in the inner angle; article 3 oblique, with five setae, one proximal and two distal plumose.

MAXILLA ( Fig. 11E View Fig ). Slender, bent distally with five teeth.

MANDIBLE ( Fig. 11F View Fig ). Symmetrical; palp with three articles, article 1 rectangular, almost half the length of second; article 2 with an apical seta; article 3 with eight serrated robust setae. Incisor with three teeth; lacinia mobilis with four denticles and molars rounded.

PEREOPOD 1 ( Fig. 12A View Fig ). Subchelate; carpus triangular, rounded distally, with three long setae; propodus oval, 2 times as long as wide, palm projected medially with crenulated margin, proximal region with a row of four setae, distal region with a group of smooth setae; dactylus reaching the projection of the palm with two long setae in internal distal angle.

PEREOPODS 2–3 ( Fig. 12B–C View Fig ). Similar in shape and size. Carpus triangular, with three apical setae; propodus sub-cylindrical, 2.2 times as long as wide in P2 and 2.7 times as long as wide in P3, internal margin with scales, ventrodistal angle with a denticulate sensory spine; distal margin of dactylus with a spine and a group of smooth and plumose setae.

PEREOPODS 4–7 ( Fig. 12D–G View Fig ). Similar in shape and size. Carpus sub-pentagonal with a sensory spine on the ventrodistal margin, external margin with a plumose sensory seta; propodus cylindrical, slightly curved, internal margin with setulated scales; ventrodistal angle with a denticulate sensory spine and two pectinate spines in P7; dactylus with a denticle in the internal proximal margin.

PLEOPOD 1 ( Fig. 13A View Fig ). Protopod with five retinaculae; exopod operculiform, 3.3 times as wide as the endopod, surrounded distally by 26 plumose setae; endopod slightly shorter than exopod, apically rounded with seven plumose setae.

PLEOPOD 2 ( Fig. 13B View Fig ). Exopod cylindrical, longer than endopod, surrounded distally by eight plumose setae; endopod with five plumose setae.

UROPODAL PROTOPOD ( Fig. 13F View Fig ). Rectangular, 1.6 times as long as wide with a row of plumose setae on the inner margin.

UROPODAL ENDOPOD ( Fig. 13F View Fig ). Oval, 1.3 times as long as wide, distal region with smooth and plumose sensory setae.

UROPODAL EXOPOD ( Fig. 13G View Fig ). Oval with a strong emargination on the distal region; margin with approximately 20 smooth setae and 30 plumose setae.

Distribution and habitat

Known only in the type locality, Estacahuite Beach, Oaxaca. In coral rock; subtidal (4 m).

Remarks

Mesanthura estacahuitensis sp. nov. differs from previously recorded species of Mesanthura by the following unique characteristics: pigmentation pattern, last article of mandibular palp with eight setae, palm of pereopod 1 crenulated and projected medially. Mesanthura estacahuitensis sp. nov. is more similar to M. nubifera , described from Turner Island, Sonora than to the other species ( Table 1 View Table 1 ) as follows: (1) projection to palm of pereopod 1, (2) mandible, (3) shape and dorsal ornamentation of the telson. However, in M. estacahuitensis sp. nov. the distal article of the antennular flagellum has four aesthetascs, flagellum of antenna with four articles, last article of maxillipedal palp with three plumose setae, internal margin of the carpus and propodus of the pereopods 2–7 with setulated scales and 1–2 simple setae, apical region of the telson with three pairs of simple setae and one pair of plumose setae, while M. nubifera has antennule with five aesthetascs, antennal flagellum with one article, last article of maxillipedal palp with one plumose seta and two pectinate setae, carpus and propodus of the pereopods 2–7 with cuticular scales and up to seven simple setae, and telson with nine pairs of apical setae.

Table 1. Comparison between the species of Mesanthura Barnard, 1914 recorded in the Mexican Pacific and Mesanthura antenniformis sp. nov., Mesanthura estacahuitensis sp. nov. from Oaxaca.

Character / species M. occidentalis Menzies & Barnard, 1959 M. nubifera Wägele, 1984 M. antenniformis sp. nov. M. estacahuitensis sp. nov.
Locality Point Conception, California Turner Island, Sonora Estacahuite Beach, Oaxaca Estacahuite Beach, Oaxaca
Body length 7.5 mm 14 mm 8 mm 6.8 mm
Last flagellar article of A1 3 aesthetascs 7 setae 5 aesthetascs 4 setae 5–6 aesthetascs 5 setae 4 aesthetascs 3 setae
Distal margin of second article of A2 peduncle Straight Straight Internal angle projected Straight
Last article of the mandibular palp 5 setae 10 setae 5–6 setae 8 setae
Palm of P1 Medially projected Medially projected Straight Medially projected
Propodus of P2 Cuticular and setulated scales Cuticular scales Setulated scales Setulated scales
Apex of telson Rounded with 8 pairs of setae Slightly rounded with 9 pairs of setae Depressed with 6 pairs of setae Rounded with 5 pairs of setae
Setae on telson surface Some shorts None Some shorts None

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Isopoda

Family

Anthuridae

Genus

Mesanthura

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF