Research Article |
Corresponding author: Paula C. RodrÍguez-Flores ( paularodriguezflores@gmail.com ) Academic editor: Ingo S. Wehrtmann
© 2020 Paula C. RodrÍguez-Flores, Enrique Macpherson, Annie Machordom.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
RodrÍguez-Flores PC, Macpherson E, Machordom A (2020) A new species of squat lobster of the genus Hendersonida (Crustacea, Decapoda, Munididae) from Papua New Guinea. ZooKeys 935: 25-35. https://doi.org/10.3897/zookeys.935.51931
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Hendersonida parvirostris sp. nov. is described from Papua New Guinea. The new species can be distinguished from the only other species of the genus, H. granulata (Henderson, 1885), by the fewer spines on the dorsal carapace surface, the shape of the rostrum and supraocular spines, the antennal peduncles, and the length of the walking legs. Pairwise genetic distances estimated using the 16S rRNA and COI DNA gene fragments indicated high levels of sequence divergence between the new species and H. granulata. Phylogenetic analyses, however, recovered both species as sister species, supporting monophyly of the genus.
Anomura, mitochondrial genes, morphology, West Pacific
Squat lobsters of the family Munididae Ahyong, Baba, Macpherson & Poore, 2010 are recognised by the trispinose or trilobate front, usually composed of a slender rostrum flanked by supraorbital spines (
During a recent expedition to Papua New Guinea in August-October 2010 (BIOPAPUA) (
Specimens were collected using beam trawls in August-October 2010 (BIOPAPUA) expedition to Papua New Guinea. The types are deposited in the collections of the Muséum national d’Histoire naturelle, Paris (
Tissue of each specimen was isolated from the muscle of pereopod 5 and homogenised overnight with 20 µl proteinase K in 180 µl of buffer ATL (QIAGEN). The extraction was performed using DNeasy Blood and Tissue Kit following manufacturer instructions (QIAGEN). Two molecular markers were amplified: a fragment from the mitochondrial cytochrome oxidase subunit I (COI) using primers LCO1490 (
The pre-mixing of the PCR reagents was built in 25 µl total volume, which included 2 µl of DNA extracted, 0.2 mM of each deoxyribonucleotide triphosphate (dNTP), 0.2 µM of each primer forward and reverse, 2U of MyTaq polymerase (Bioline), 5 µl of 5× buffer solution with MgCl2 and sterilised H2O. PCR amplification was performed with a thermal cycle including an initial denaturation of 94–95 °C for 1–4 min and 40 cycles with 95 °C for 1 min, annealing in 42–45 °C for 1 min followed by an extension set on 72 °C for 1 min. A final extension cycle at 72 °C was set for 10 min. The amplicons were visualised in agarose 1% gels and purified using ExoSAP-IT™ PCR Product Cleanup Reagent (Thermo Fischer) before sequencing. The purified products were sent to Secugen S.L. (Madrid) for DNA Sanger sequencing.
The nucleotide sequences of both forward and reverse were visualised and assembled with Sequencher 4.10.1 software package (Gene Codes Corp.). Multiple sequence alignment for the 16S genes was carried out in MAFFT (
Bayesian phylogenetic analysis was performed in MrBayes v3. 2. 1 (
Our results demonstrated the existence of two species of Hendersonida supported both by molecular and morphological characters. Both species formed a clade with high Bayesian posterior probability (Fig.
Phylogenetic hypothesis based on mitochondrial molecular data (COI and 16S) represented by a tree obtained by Bayesian inference, including Bayesian posterior probabilities. To test the monophyly of Hendersonida, we have included all genetic data available from species of Paramunida included in
Superfamily Galatheoidea Samouelle, 1819
Family Munididae Ahyong, Baba, Macpherson & Poore, 2010
Genus Hendersonida Cabezas & Macpherson, 2014
Holotype
: Biopapua stn CP3645, 24/8/2010, 06°46.394'S, 147°50.605'E, 403–418 m: ovigerous female, 8.9 mm (
Rostrum shorter than supraocular spines, each supraocular spine with small lateral spine. Carapace dorsal surface granulated with few scattered minute spines. Thoracic sternites with numerous arcuate striae, sternite 4 narrowly contiguous to sternite 3. Abdominal somites 2 and 3 spinose. Distomesial spine of antennal article 2 reaching end of article 3. Extensor distal margin of maxilliped 3 armed. Pereopods 2–4 long and slender, merus ca. 25 times as long as wide.
Carapace : Slightly broader than long; dorsal surface covered with numerous granules and few scattered minute spines, with few short simple setae; epigastric region with row of 6 minute spines; mesogastric region slightly convex, unarmed; cervical groove distinct; cardiac and anterior branchial regions slightly circumscribed; cardiac region with anterior transverse row of four minute spines, and two minute spines posterior to it; each branchial region with 2–4 small spines near lateral borders; frontal margin slightly concave; lateral margins convex; anterolateral spine reaching sinus between rostral and supraocular spines. Rostrum very short; supraocular spines longer than rostrum, each spine with additional small lateral spine; margin between rostral and supraocular spines concave.
Sternum : Thoracic sternites with numerous arcuate striae; sternite 3 width less than half width of sternite 4, anterior margin nearly straight; sternite 4 with anterior margin moderately elongate, narrowly contiguous to sternite 3; sternite 7 with numerous granules.
Abdomen : Somites 2 and 3 each with some small or moderate–sized spines on anterior and posterior ridges, two median spines larger than others; posterior ridge of somite 4 without distinct single median spine.
Eyes : Large, cornea dilated, much wider than eyestalk.
Antennule : Article 1 barely exceeding corneae, with distomesial spine slightly shorter than distolateral; ca. twice as long as wide; lateral margin without fringe of long setae, with distal slender portion ca. half as long as proximal inflated portion.
Antenna : Anterior prolongation of article 1 overreaching antennular article 1 by ca. one-fourth of its length; article 2 shorter than article 3 and slightly longer than wide, ventral surface with small scales; distomesial spine well developed, reaching end of article 3, and clearly not reaching midlength of anterior prolongation of article 1, distolateral angle unarmed; article 3 twice longer than wide, unarmed.
Maxilliped 3: Ischium 1.5 times length of merus measured along dorsal margin, distoventrally bearing one spine; merus with two or three small spines on flexor margin, extensor margin with distal spine.
Pereopod 1: Lost in holotype, only merus preserved in paratype. Merus 2.5 times carapace length, ca. 15 times longer than high, with row of spines along mesial margin.
Pereopods 2–4: Similar, long and slender, with minute granules and short scales on ventrolateral sides of meri, carpi and propodi; scales with short setae; extensor and flexor margins with numerous long plumose setae; pereopod 2 6.0 times carapace length, merus 3.0 times longer than carapace, ca. 25 times as long as wide, 1.8 times as long as propodus; propodus 20 times as long as wide, and 1.7 times dactylus length; merus with well-developed spines along extensor border, flexor margin with few spines; carpus with distal spine on extensor and flexor margin; propodus with some small movable spines along flexor margin; dactylus slightly curved, with longitudinal carinae along mesial and lateral sides, ventral border, under flexor margin, unarmed; pereopods 3 and 4 of similar length as pereopod 2, with similar spinulation and segment proportions as pereopod 2.
Colour in life : Base colour of carapace light orange, gastric region reddish; granules and spines orange. Rostrum and supraocular spines reddish. Abdominal somites 1–4 light orange, with scales and granules orange or reddish; somites 5 and 6 and telson whitish. Pereopods 2–4 light orange, spines along flexor margins reddish, spines along flexor margins whitish; distal portion of meri, carpi, and propodi and proximal part of carpi, propodi, and dactyli with reddish band, distal half of dactyli whitish.
Hendersonida parvirostris sp. nov. ovigerous female holotype, 8.9 mm (
GenBank accession numbers: 16S MT252616–MT252617, and COI MT250542–MT250543 (Fig.
From the Latin, parvus, little, and rostrum, in reference to the small size of the rostral spine.
The genus Hendersonida was erected for one rare species, H. granulata (Henderson, 1885) known from several localities of the western Pacific, clearly differentiable from all species of the genus Paramunida Baba, 1988 (
Two conspicuous diagnostic characteristics differentiate the Hendersonida genus from Paramunida: the granulated surface of the carapace; and the long distomesial spine of antennal article 2, almost reaching the end of the anterior prolongation of article 1 (
The two species of Hendersonida can be differentiated by the following characters:
Here, we demonstrate the existence of a new species of the formerly monotypic genus Hendersonida, based on morphology, molecular characters, and phylogenetic information.
The genetic distances observed between the new species and H. granulata were 11% for 16S and 16% for COI. These values imply high levels of genetic divergence, even exceeding the mean divergence reported for other munidid species in previous studies (
We thank our colleagues who made specimens available for this study: P. Bouchet, L. Corbari, B. Richer de Forges, A. Crosnier, S. Samadi, and P. Martin-Lefèvre of