taxonID	type	description	language	source
03D1372DFF95FFD478F0F989C0397CEB.taxon	diagnosis	Diagnosis. Palate smooth, without longitudinal ridge. Carapace more than twice longer than wide, with 2 strong lateral horns (spines), 9 pairs of anterolateral teeth, including external orbital teeth and lateral horns; carapace finely granular, with yellowish-orange, brownish-yellow, or vinaceous brown, covered over dorsal surface with reticulum of abundant, small rounded white spots; inter-regional sulci present but not conspicuous. Rostrum narrow, short, 2 or 4 teeth; superior orbit border divided by 2 large, V-shaped incisions. Spine at epistome region present or absent. 1 or 2 spines at carpus of chelae; manus bearing 5 longitudinal carinae. Fifth leg segments flattened, unarmed. Spiniform borders at the second abdominal segment; sixth segment narrow in males (not as narrow, “ T ” - shaped as in Callinectes), with sinuous margins, attenuated tip.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF95FFD478F0F989C0397CEB.taxon	description	Redescription. Light yellowish-orange, brownish-yellow, or vinaceous brown, with reticulum of white, rounded spots on dorsal carapace. Spots not evenly distributed on carapace; anterior area, especially gastric region, with smaller spots; spots sparser, larger in chelipeds. Ventral surface light yellow or light cream, spots absent. Dactyl tip of ambulatory legs yellow. Color may not persist in long ethanol preservation. Carapace more than twice longer than wide, produced laterally into strong horns (spines); fine granulate texture, visible under magnification. Inter-regional sulci detectable, mainly in mesogastric region, but not too deep. Posterolateral angle spiny or nearly rounded. 9 pairs of anterolateral teeth, including external orbit teeth and lateral horns, densely fringed beneath; first 3 anteriormost teeth similar in shape, size, fourth wider; sixth and seventh the sharpest; lateral horn very prominent, longer than the sixth, seventh together; lateral horn, sixth, seventh lateral teeth slightly curved forwards, with white tips. Front (frontal region) commonly hirsute. Rostrum narrow, short, much less advanced than outer orbit angles; 2 or 4 teeth. Supraorbital border with 3 teeth, a lobe on each side; inner orbit tooth less prominent than outer; superior orbit border with 2 V-shaped incisions, inner deeper, more open than outer, intervening lobe subtruncate, fairly wide; inner tooth relative to orbit small, little prominent, less advanced than others; rostrum: inferior orbit border with wide, triangular incision between inner, outer teeth. Chelipeds short, stout. Basis and ischium short, flattened; ischium with short tooth at distal end. Merus elongated, nearly pyramid-shaped, attenuated towards basis; 3 spines on inner face, generally larger in size outwards; tooth near distal end relatively obsolete; transverse sinus more marked near distal end; obsolete tooth on outer border near distal end. Carpus short, cylindrical, armed with 1 or 2 sharp spines; 2 denticles on dorsal face, both leading proximally to fairly developed carinae. Palm elongated, cylindrical, attenuated towards both ends; 5 longitudinal carinae; 2 spines, 1 at the proximal end, near the carpus joint, second at distal end, above dactyl base; 2 poorly developed distal prominences near dactyl, dorsal prominence relatively denticular, lateral prominence shorter and stouter. Articles of ambulatory and swimming legs wide, flattened. Tip of ambulatory legs yellow; merus arcuate on external border, unarmed. Second abdominal segment laterally produced into 2 strong spines; sixth segment narrower distally, with sinuous margins; telson attenuated. First male pleopods elongated, slender; base fringed below; extended well beyond midpoint of telson; outer, ventral faces densely covered with small bristles on nearly the entire basal portion, absent on dorsal surface; terminal portion with single row of bristles located on ventral face; tip rather flattened, spoon-shaped.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF92FFD678F0FB60C6DB7EA2.taxon	materials_examined	Type locality: Brazil. Known range: from Massachusetts, USA to Mar del Plata, Argentina. In Brazil, from the state of Ceará to Rio Grande do Sul (Williams 1984, Melo 1996, Scelzo 2001). Material examined. MEXICO (Atlantic coast): 1 male (CL 30.41 mm) UNAM 9639: Punta Estrella, Puerto Morelos, Quintana Roo, 19. ii. 1972, (J. C. Nates, A. Cantú, J. L. Villalobos, D. Valle & P. Schmidstorf coll.); 1 male (CL 23.50 mm) UNAM 3579: El Morro de la Mancha, Veracruz, 20. viii. 1984, (D. Baños coll.). COSTA RICA (Atlantic coast): 1 male (CL 47.50 mm) and 1 female (CL 25.64 mm) UCR 2017 - 02: Tortuguero Beach, Limon, 9. i. 1995, (J. Cortés coll.); 1 male (CL 15.45 mm) and 1 female (CL 27.20 mm) UCR 2470 - 10: N. O. Pájaros Island, Moín, Limón, 25. vii. 2006, (K. Rodrigues & M. Mug coll.); 2 females (CL 33.37 mm and 28.70 mm), CCDB 2930: Playa Negra, close to Estero Negro, Carretera, Cahuita, 22. v. 2010, (F. L. Mantelatto et al. coll.). VENEZUELA: 1 female (CL 42.41 mm) CCDB 3635: La Restinga (El Saco), 25. viii. 2011, (J. Bolaños coll.). BRAZIL: 1 male (CL 11.34 mm), DOUFPE 6880: Meireles, Fortaleza, Ceará, 14. vii. 1977 (coll. not given); 2 females (CL 24.10 mm and 18.86 mm), CCDB 3391: Pirangi Beach, Parnamirim, Rio Grande do Norte, 8. vi. 2011, (R. Robles coll.); 1 male (CL 10.46 mm), DOUFPE 6873: Tambaú, Paraíba, 01. vii. 1964, (coll. not given); 2 males (CL 35.63 mm and 45.31 mm) DOUFPE 6876: Tambaú, Paraíba, 25. ix. 1972, (coll. not given); 1 male (CL 10.51 mm), DOUFPE 6893: Candeias, Pernambuco, 30. vii. 1988, (coll. not given); 1 male (CL 29.42 mm), DOUFPE 6871: Jaraguá Beach, Maceió, Alagoas, 28. vi. 1981, (coll. not given); 1 male (CL 32.13 mm), CCDB 5936: Praia de Maragogi, Maragogi, Alagoas, 05. x. 2013, (E. A. Souza-Carvalho & F. L. Carvalho coll.); 1 male (CL 17.24 mm), DOUFPE 6861: Santa Cruz Cabrália, Bahia, 10. ii. 1999, (coll. not given); 2 males (CL 48.59 mm and 45.71 mm), CCDB 3255: Macaé, Rio de Janeiro, 10. vii. 2011, (R. C. Costa coll.); 1 male (CL 52.39 mm), CCDB 2725: Ubatuba Bay, Ubatuba, São Paulo, 30. xi. 2005, (F. L. Mantelatto coll.); 1 male (CL 36.72 mm), CCDB 1536: Ubatuba, São Paulo, 17. viii. 2011, (D. Rosa coll.); 2 males (CL 50.75 mm and 47.13 mm), CCDB 754: Caraguatatuba, São Paulo, vii. 2001, (F. L. Mantelatto coll.); 1 male (CL 29.88 mm) CCDB 291: Guaiuba Beach, Guarujá, São Paulo, 22. x. 2011, (F. Carvalho et al. coll.); 1 male (CL 29.30 mm), CCDB 3700: Peruíbe, São Paulo, 14. xii. 2011, (L. Zupolini & R. Amaral coll.); 1 male (CL 24.31 mm), CCDB 3208: Boqueirão Norte Beach, Ilha Comprida, São Paulo, 17. iv. 2011, (F. L. Mantelatto et al. coll.); 1 male (CL 14.44 mm), CCDB 3182: Boqueirão Sul Beach, Ilha Comprida, São Paulo, 17. iv. 2011, (R. C. Costa et al. coll.); 2 males (CL 15.06 mm and 30.35 mm) and 1 female (CL 34.68 mm), CCDB 3241: Cananéia, São Paulo, 18. iv. 2011, (T. M. Dawanso et al. coll.); 1 female (CL 30.58 mm) and 1 male (CL 51.61 mm), CCDB 3516: close to São Francisco do Sul, Santa Catarina, 10. viii. 2010, (S. Moura coll.); 3 females (CL 22.19 mm, 35.12 mm and 27.69 mm) and 3 males (18.57 mm, 23.77 mm and 27.44 mm), CCDB 1461: São Francisco do Sul, Santa Catarina, 28. v. 2011, (A. L. Castilho coll.); 1 female (CL 35.02 mm), CCDB 1457: São Francisco do Sul, Santa Catarina, 25. v. 2011, (A. L. Castilho coll.); 1 female (CL 41.52 mm), CCDB 990: Santinho Beach, Florianópolis, Santa Catarina, 28. i. 2004, (F. L. Mantelatto coll.).	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF92FFD678F0FB60C6DB7EA2.taxon	diagnosis	Diagnosis. Rostrum with 4 teeth, the 2 median teeth more widely separated than outer ones; spine at the epistome region present, not much advanced in relation to the front; 2 sharp spines in carpus.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF92FFD678F0FB60C6DB7EA2.taxon	description	Redescription. Yellowish orange, brownish yellow, greyish or olive brown, abundantly covered over dorsal surface with small, rounded white spots. Front (frontal region) having a spine in the epistome region, between antennules, not much advanced in relation to front. Rostrum armed with 4 small teeth, the 2 median more prominent, more advanced, more widely separated from each other than outer ones. Carpus of chelipeds with 2 short but developed, sharp spines, one on the outer face, second on inner face of carpus; outer spine continued proximally as obsolete carina. Male gonopods (first pair of modified pleopod) generally overreaching the telson tip and crossed over by its final portions; tip moderately attenuated.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF92FFD678F0FB60C6DB7EA2.taxon	discussion	Remarks. We attempted several times to reach the holotype from Muséum national d’Histoire naturelle in order to confirm the condition of the type. However, we have not received response whatsoever at the time of writing this manuscript. Based on our set of specimens analyzed, various subtle differences are found in juveniles in contrast to adult and larger specimens. Inter-regional sulci on the dorsal surface of the carapace are more marked in juveniles, resembling the equivalent condition in A. mexicanus. Consequently, the inner branchial lobule appears more prominent in younger individuals. The first four anterolateral teeth, except the outer orbital one, are similar in size and smaller than the consecutive teeth. The lateral horn is apparently sharper and proportionally longer. The spine in the epistome is less prominent. Outer teeth in the rostrum are less developed and prominent, while the inner ones are similar to the adults’; the outer incision in the superior orbit border is nearly unapparent. Finally, the transverse sinus in the cheliped distal portion of the merus is not as deep and marked. Also in juveniles, the caudal extremity of the telson is less attenuated, nearly triangular in shape, similar to the condition in females. Furthermore, some other discrepancies are observed exclusively in smaller specimens rather than in every juvenile. The merus of the swimming legs, for instance, is slightly shorter in proportion compared to larger juveniles. In one specimen, the ischium of the first pair of ambulatory legs presented 2 instead of 1 tubercular prominence at its distal end. Some characteristics stated in previous descriptions may also be incongruent or inconsistent. The diagnostic “ one spine at the distal end of manus ” in Rathbun (1930: 135) is not informative in distinguishing both species. Furthermore, the description of the male gonopods in Rodríguez (1982) does not entirely suit the observations made in this study. The ornamentation pattern suggested by the author does not apply to the whole length of the structure as the basal portion is covered with setae practically in its entirety.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF90FFD878F0F8A5C1B17E76.taxon	materials_examined	Type locality: Mexico. Known range: from Baja California, Mexico to northern Chile (for detailed references see Rathbun 1930, Garth & Stephenson 1966, Retamal & Arana 2000). Material examined. MEXICO (Pacific coast): 1 male (CL 28.22 mm — holotype photography), MFN 301; 1 female (CL 22.24 mm), NMNH 60003: Ballena Bay, Baja California, 16. iii. 1911, (US Fish Commission coll.); 1 male (CL 15.66 mm), NMNH 207834: Magdelena Bay, Baja California, 02. xii. 1931, (S. A. Glassell coll.); 1 male (CL 21.38 mm) and 2 females (CL 18.74 mm and 16.71 mm), UNAM 3513: Perula Beach, Chamela Bay, Jalisco, 15. vi. 1984, (J. C. Nates, J. L. Villalobos & A. Cantu coll.). NICARAGUA (Pacific coast): 1 male (CL 25.61 mm), NMNH 29316: Corinto, data not given, (coll. not given). COSTA RICA (Pacific coast): 2 females (CL 23.03 mm and 23.41 mm), CCDB 5937: Playa de Tamarindo, Tamarindo, 19. vii. 2013, (E. A. Souza-Carvalho & F. L. Carvalho coll.); 1 male (CL 22.90 mm), UCR 2430 - 04: Naranja Beach, Papagayo Gulf, Santa Elena, La Cruz, Guanacaste, 15. vii. 2005, (R. Vargas coll.); 1 female (CL 42.40 mm) UCR 835 - 001: Nicoya Gulf, 5. v. 1981, (coll. not given), det. A. Dittel; 1 female (CL 20.52 mm), CCDB 2936: Puntarenas, 25. v. 2010, (F. L. Mantelatto et al. coll.); 1 male (CL 29.60 mm) and 5 females (CL 28.90 mm, 26.70 mm, 27.40 mm, 28.40 mm and 24.20 mm), UCR 1382: Organo Beach, Puntarenas, 16. v. 1991, (coll. not given), det. A. Dittel; 6 females (CL 40.20 mm, 37.80 mm, 35.70 mm, 36.10 mm, 37.80 mm and 37.40 mm) UCR 401: Caldera, Puntarenas, 29. iv. 1970, (R. Saenz coll.); 2 males (CL 47.60 mm and 55.40 mm) UCR 873: Cano Island, 17. xii. 1970, (V. Cruz coll.); 1 male (CL 12.04 mm), ULLZ 9113: eastern Pacific Coast, 18. vii. 2005, (F. L. Mantelatto coll.); 1 male (CL 14.76 mm), CCDB 1716: Pacific, v. 2005, (R. Vargas coll.); 2 males (CL 14.43 mm and 17.20 mm) and 1 juvenile (CL 11.03 mm), NMNH 20607: Cocos Island, 28. ii. 1891 (US Fish Commission coll.). PANAMA: 1 female (CL 25.06 mm), NMNH 111712: San Jose Island, Perlas Archipelago, 17. v. 1944, (J. P. E. Morrison coll.); 2 males (CL 22.64 mm and 28.08 mm), NMNH 111673: San Jose Island, Perlas Archipelago, 26. v. 1944, (J. P. E. Morrison coll.); PERU: 1 male (CL 29.15 mm), NMNH 77097: Paita, x. 1926, (W. L. Schmitt coll.); 3 females (CL 22.12 mm, 21.59 mm and 21.33 mm) and 1 male (CL 18.47 mm), NMNH 111674: Nanora Bay, Sechura Bay, 16. v. 1941, (M. J. Lobell coll.); 2 males (CL 29.86 mm and 27.69 mm), NMNH 111853: Chilca Bay, 16. iv. 1941, (M. J. Lobell coll.).	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF90FFD878F0F8A5C1B17E76.taxon	diagnosis	Diagnosis. Rostrum with 2 teeth; spine at the epistome region absent; sharp spine on the cheliped carpus.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF90FFD878F0F8A5C1B17E76.taxon	description	Redescription. Dark yellowish orange, brownish yellow, or vinaceous brown, abundantly covered over dorsal surface with small, rounded white spots; spotted pattern faint on chelipeds. Front (frontal region) not having a spine in the epistome region, between antennules. Rostrum armed with 2 prominent teeth. Transverse sinus at distal end of cheliped merus shallow, marked; one spine at inner border of carpus; outer spine reduced to denticle leading to a developed carina. Male gonopods extended well beyond midpoint of telson.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
03D1372DFF90FFD878F0F8A5C1B17E76.taxon	discussion	Remarks. The holotype, preserved in dry conditions, was examined by the collection curator (C. O. Coleman, Museum für Naturkunde, Berlin), who sent us some detailed photos. From these records, the shape and the pattern of various structures, e. g. rostrum and carapace, connect with certainty the specimen to the description proposed above. Apart from the discrete characters in the descriptions, a myriad of other features subtly differs between the species. For instance, in A. mexicanus, the inter-regional furrows are more profound and marked, while the inner branchial lobule is more prominent; anterolateral teeth are apparently longer and narrower; the lateral horn and the merus of the swimming legs are proportionally longer; and the epistome region lacking a spine is more concave and profound. Another character that deserves attention is the supraorbital inner lobe (tooth sensu Rathbun 1930 and Garth & Stephenson 1966), which is narrower and nearly rectangular in shape or virtually similar to A. cribrarius, contrary to previous descriptions. Such character exhibited a variation in different populations of A. mexicanus. Analyzed specimens from Costa Rica possessed wider lobes, resembling the condition observed in A. cribrarius. Conversely, analyzed specimens from the Mexican Pacific, presented narrower structures, in accordance to previous descriptions for the genus. Further, the description of the male gonopods in Garth & Stephenson (1966) is imprecise, as it does not consider the basal ornamentation. An illustrated, simplified key for the species of the genus Arenaeus is given in Fig. 5.	en	Zupolini, Lucas L., Magalhães, Tatiana, Pileggi, Leonardo G., Mantelatto, Fernando L. (2017): Taxonomic revision of the speckled crabs, genus Arenaeus Dana, 1851 (Brachyura: Portunidae) based on morphological and molecular data. Zootaxa 4273 (3): 362-380, DOI: 10.11646/zootaxa.4273.3.3
