Abstract
Speciose populations of small xanthoid crabs on offshore banks and reefs of the northern Gulf of Mexico include a new species that is not assignable to presently named genera. Morphological diagnoses of the new genus and species are underpinned by previously published gene sequence analyses, originally misattributed to another species but now known to apply to this taxon. Herein named Guinope tiara n. gen., n. sp., the species shows molecular phylogenetic affinities with the family Linnaeoxanthidae Števčić, 2005, an ally of panopeid and pseudorhombilid crabs. Specimens from Occulina banks off the Florida Atlantic coast, previously regarded to represent Garthiope barbadensis (Rathbun, 1921), are not that species but instead morphologically assignable to Guinope n. gen. Whether they represent variants of Guinope tiara n. gen, n. sp. or a second species of the genus awaits the collection of fresh materials for DNA analyses.
References
Alcock, A. (1900) Materials for a carcinological fauna of India. No. 6. The Brachyura Catometopa, or Grapsoidea. Journal of the Asiatic Society of Bengal, 69, 279–456.
https://doi.org/10.5962/bhl.title.15344
Dana, J.D. (1851) Conspectus Crustaceorum quæ in Orbis Terrarum circumnavigatione, Carolo Wilkes e Classe Reipublicæ Fœderatæ Duce, lexit et descripsit. Proceedings of the Academy of Natural Sciences of Philadelphia, 5, 247–254.
Felder, D.L, Álvarez, F., Goy, J.W. & Lemaitre, R. (2009) Decapoda (Crustacea) of the Gulf of Mexico, with comments on the Amphionidacea. In: Felder, D.L. & Camp, D.K. (Eds.), Gulf of Mexico Origin, Waters, and Biota. Vol. 1. Biodiversity. Texas A&M University Press, College Station, Texas, pp. 1019–1104.
Felder, D.L. & Thoma, B.P. (2010) Description of Etisus guinotae n. sp., and discussion of its recent discovery in the Gulf of Mexico (Brachyura, Decapoda, Xanthidae). In: Castro, P., Davie, P.J.F., Ng, P.K.L. & Richer de Forges, B. (Eds.), Studies on Brachyura: a homage to Daniele Guinot. Brill, Leiden, pp. 117–138.
https://doi.org/10.1163/ej.9789004170865.i-366.78
Gore, R.H., Van Dover, C.L. & Wilson, K.A. (1981) Studies on decapod Crustacea from the Indian River Region of Florida. XX. Micropanope barbadensis (Rathbun, 1921): the complete larval development under laboratory conditions (Brachyura, Xanthidae). Journal of Crustacean Biology, 1, 28–50.
https://doi.org/10.2307/1548203
Guinot, D. (1967) Recherches préliminaires sur les groupements naturels chez les Crustacés Décapodes Brachyoures. II. Les anciens genres Micropanope Stimpson et Medaeus Dana. Bulletin du Muséum national d’Histoire naturelle, Paris, Série 2, 39 (2), 345–374.
Guinot, D. (1990) Établissement du genre Garthiope gen. nov., ses relations avec le genre Coralliope Guinot, 1967, et leurs affinités avec les Trapeziidae sensu lato (Crustacea Decapoda Brachyura). Bulletin du Muséum national d’Histoire naturelle, Section A, Zoologie, Biologie et Ecologie Animales, Paris, Série 4e, 12, 469–487
Lai, J.C.Y., Mendoza, J.C.E., Guinot, D., Clark, P.F. & Ng, P.K.L. (2011) Xanthidae MacLeay, 1838 (Decapoda: Brachyura: Xanthoidea) systematics: A multi-gene approach with support from adult and zoeal morphology. Zoologischer Anzeiger - A Journal of Comparative Zoology, 250, 407–448.
https://doi.org/10.1016/j.jcz.2011.07.002
Lasley, R.M., Lai, J.C.Y. & Thoma, B.P. (2013) A new genus for Chlorodiella longimana (H. Milne Edwards) supported by morphology and molecular data, with a preliminary phylogeny of the Chlorodiellinae (Crustacea: Decapoda: Xanthidae). Invertebrate Systematics, 27, 379–390.
https://doi.org/10.1071/IS12075
Lemaitre, R. (1984) Decapod crustaceans from Cay Sal Bank, Bahamas, with notes on their zoogeographic affinities. Journal of Crustacean Biology, 4, 425–447.
https://doi.org/10.2307/1548042
MacLeay, W.S. (1838) Illustrations of the Annulosa of South Africa; being a portion of the objects of natural history chiefly collected during an expedition into the interior of South Africa, under the direction of Dr. Andrew Smith, in the years 1834, 1835, and 1836; fitted out by the “Cape of Good Hope Association for Exploring Central Africa.” In: Smith, A. (Ed.), Illustrations of the zoology of South Africa investigations. Smith, Elder & Co., London, pp. 1–75, pls. 1–4.
Mendoza, J.C., Clark, P.F. & Ng, P.K.L. (2012) The identity of Pilumnoplax acanthomerus Rathbun, 1911 (Crustacea: Decapoda: Brachyura: Xanthidae), with new records from the central and western Pacific. Zootaxa, 3367 (1), 211–221.
https://doi.org/10.11646/zootaxa.3367.1.20
Milne-Edwards, A. (1880a) Études sur les Xiphosures et les Crustacés podophthalmaires. In: Mission scientifique, Recherches zoologiques pour servir à l’histoire de la faune de l’Amérique Centrale et du Mexique, Cinquième partie, 7, 265–312, pls. 31A + 44 + 49–54.
Milne-Edwards, A. (1880b) Études sur les Xiphosures et les Crustacés podophthalmaires. In: Mission scientifique, Recherches zoologiques pour servir à l’histoire de la faune de l’Amérique Centrale et du Mexique, Cinquième partie, 8, 313–368, 1–8 (unpaginated), pls. 55–61.
Ortmann, A.E. (1893) Die Decapoden-Krebse des Strassburger Museums, mit besonderer Berücksichtigung der von Herrn Dr. Döderlein bei Japan und bei den Liu-Kiu-Inseln gesammelten und zur Zeit im Strassburger Museum aufbewahrten Formen. VII. Theil. Abtheilung: Brachyura (Brachyura genuina Boas) II. Unterabtheilung: Cancroidea, 2. Section: Cancrinea, 1. Gruppe: Cyclometopa. Zoologische Jahrbücher, Abtheilung für Systematik, Geographie, und Biologie der Thiere, 7, 411–495.
https://doi.org/10.5962/bhl.part.24064
Rathbun, M.J. (1898) The Brachyura of the biological expedition to the Florida Keys and the Bahamas in 1893. Bulletin from the Laboratories of Natural History, State University of Iowa, 2, 250–294.
Rathbun, M.J. (1911) The Percy Sladen Trust expedition to the Indian Ocean in 1905, under the leadership of Mr. J. Stanley Gardiner. Vol. III. No. XI. Marine Brachyura. The Transactions of the Linnean Society of London, Series 2, Zoology, 14, 191–261.
https://doi.org/10.1111/j.1096-3642.1911.tb00084.x
Rathbun, M.J. (1921) Report on the Brachyura collected by the Barbados-Antigua Expedition from the University of Iowa in 1918. University of Iowa Studies in Natural History, 9, 65–90, pls. 1–3.
Rathbun, M.J. (1930) The cancroid crabs of America of the families Euryalidae, Portunidae, Atelecyclidae, Cancridae and Xanthidae. Bulletin of the U.S. National Museum, 152, i–xvi + 1–609.
https://doi.org/10.5479/si.03629236.152.i
Reed, J.K., Gore, R.H., Scotto, L.E. & Wilson, K.A. (1982) Community composition, structure, areal, and trophic relationships of decapods associated with shallow-and deep-water Oculina varicosa coral reefs: studies on decapod Crustacea from the Indian River region of Florida, XXIV. Bulletin of Marine Science, 32, 761–786.
Smith, S.I. (1870) Notes on American Crustacea. Number I. Ocypodoidea. Transactions of the Connecticut Academy of Arts and Sciences, 2, 113–176.
https://doi.org/10.5962/bhl.part.20635
Števčić, Z. (2005) The reclassification of brachyuran crabs (Crustacea: Decapoda: Brachyura). Natura Croatica, 14, 1–159.
Števčić, Z. (2011) Addition to the reclassification of brachyuran crabs (Crustacea: Decapoda: Brachyura). Part 1. New Taxa. Natura Croatica, 20, 125–139.
Stimpson, W. (1871) Preliminary report on the Crustacea dredged in the Gulf Stream in the Straits of Florida by L.F. de Pourtales, Assist. U.S. Coast Survey. Part I. Brachyura. Bulletin of the Museum of Comparative Zoölogy at Harvard College, 2, 109–160.
Thoma, B.P. & Felder, D.L. (2012) Redescription of Hexapanopeus lobipes and its reassignment to Milnepanopeus n. gen. (Decapoda: Brachyura: Panopeidae). Journal of Crustacean Biology, 32, 141–152.
https://doi.org/10.1163/193724011X615415
Thoma, B.P., Schubart, C.D. & Felder, D.L. (2009) Molecular phylogeny of Western Atlantic representatives of the genus Hexapanopeus (Decapoda: Brachyura: Panopeidae). In: Martin, J.W., Crandall, K.A. & Felder, D.L. (Eds.), Decapod Crustacean Phylogenetics. CRC Press, Taylor & Francis Group, Boca Raton, London, New York, pp. 551–565.
https://doi.org/10.1201/9781420092592-c28
Thoma, B.P., Guinot, D. & Felder, D.L. (2014) Evolutionary relationships among American mud crabs (Crustacea: Decapoda: Brachyura: Xanthoidea) inferred from nuclear and mitochondrial markers, with comments on adult morphology. Zoological Journal of the Linnean Society, 170, 86–109.
https://doi.org/10.1111/zoj.12093
Williams, A.B. (1984) Shrimps, Lobsters, and Crabs of the Atlantic Coast of the Eastern United States, Maine to Florida. Smithsonian Institution Press, Washington, D.C. 550 pp.
Vázquez-Bader, A.R. & Gracia, A. (2004) A new genus and species of crab of the family Xanthidae MacLeay, 1838 (Crustacea: Decapoda: Brachyura) from the southwestern Gulf of Mexico. Proceedings of the Biological Society of Washington, 117, 505–513.