taxonID	type	description	language	source
038C87F59C515169FF3892B4FBD5FE55.taxon	description	(Figs. 1, 2 A – F, 3 A – D)	en	Martins, Déborah Elena Galvão, Alves-Júnior, Flavio De Almeida, Cintra, Israel Hidenburgo Aniceto, Bentes, Bianca (2026): First report of the king crab Neolithodes asperrimus Barnard, 1947 (Crustacea: Lithodidae) from the Brazilian Amazon continental slope. Zootaxa 5792 (3): 573-580, DOI: 10.11646/zootaxa.5792.3.8, URL: https://doi.org/10.11646/zootaxa.5792.3.8
038C87F59C515169FF3892B4FBD5FE55.taxon	materials_examined	Material examined. LABCRUS: 38.3.1 A, 1 male (CL 184.7 mm, PCL 170.0 mm, CW 166.1 mm), ReviZEE Program, state of Amapá, 04 ° 15.142 ' N, 049 ° 10.812 ' W, muddy bottom, 892 m depth, June 2001.	en	Martins, Déborah Elena Galvão, Alves-Júnior, Flavio De Almeida, Cintra, Israel Hidenburgo Aniceto, Bentes, Bianca (2026): First report of the king crab Neolithodes asperrimus Barnard, 1947 (Crustacea: Lithodidae) from the Brazilian Amazon continental slope. Zootaxa 5792 (3): 573-580, DOI: 10.11646/zootaxa.5792.3.8, URL: https://doi.org/10.11646/zootaxa.5792.3.8
038C87F59C515169FF3892B4FBD5FE55.taxon	diagnosis	Diagnosis. Carapace and chelipeds armed with numerous spines of small and medium sizes (Fig. 2 A – F). Carapace regions well defined (Fig. 2 A); rostrum short, with one median and two lateral spines; pterygostomial region covered with small granules (Fig. 2 B). Second abdominal somite with median plate bearing several acute spinules, especially around the edges (Fig. 2 C). Chelipeds with 5 strong spines on palm dorsal margin (Fig. 2 E – F); right cheliped strong, covered with granules on inner and outer surfaces and rows of tufts of setae in dactylus and pollex; occlusal margin of fingers with calcareous nodules proximally (Fig. 2 E); left cheliped slender, with granules and rows of tufts of setae; occlusal margin of fingers with small teeth proximally (Fig. 2 F). Walking legs slender, with increasing length posteriorly, first shortest, third longest, all covered with granules or very short blunt spines (Fig. 3 A – B); dactylus curved, dorsoventrally flattened (Fig. 3 C – D). Third walking leg length less than three times carapace length (2.89); merus longer than propodus, 5 – 6 times longer than high (5.86), shorter than the carapace length (Table 1) (modified after Macpherson 1988 a). Geographic and bathymetric distributions. Western Atlantic, Brazil: Amazon continental slope (State of Amapá [present record]) and Santa Catarina (Lianos et al. 2017). Eastern Atlantic: deep waters from Mauritania to Cape Point, South Africa (Barnard 1947; Macpherson 1988 a; Muñoz & Garcia-Isarch 2013). Note that the records of Neolithodes aff. asperrimus from Madagascar, western Indian Ocean (Macpherson 1988 b) are referable to Neolithodes indicus Padate, Cubelio & Takeda, 2020. Neolithodes asperrimus is found on muddy bottoms from the continental slope to the abyssal plain at depths of 250 to 2000 m (Barnard 1950; Macpherson 1988 a; Lianos et al. 2017).	en	Martins, Déborah Elena Galvão, Alves-Júnior, Flavio De Almeida, Cintra, Israel Hidenburgo Aniceto, Bentes, Bianca (2026): First report of the king crab Neolithodes asperrimus Barnard, 1947 (Crustacea: Lithodidae) from the Brazilian Amazon continental slope. Zootaxa 5792 (3): 573-580, DOI: 10.11646/zootaxa.5792.3.8, URL: https://doi.org/10.11646/zootaxa.5792.3.8
038C87F59C515169FF3892B4FBD5FE55.taxon	discussion	Remarks. Neolithodes asperrimus is morphologically closely related to N. agassizii, sharing several overlapping features, such as a similar pattern of spination on the carapace, median plate of the abdominal somite 2, ocular peduncles, antennae, and chelipeds; the presence of two thick spines on the posterior, terminal margin of the basisischium of the third walking leg; and also morphometric of the walking legs (see Table 2). Adult males of N. asperrimus and N. agassizii can be distinguished as follows: length of the third walking leg less than three times the carapace length in N. asperrimus vs. more than three times the carapace length in N. agassizii (Macpherson 1988 a); merus of the third walking leg shorter than carapace length in N. asperrimus vs. longer than carapace length, as observed in specimens of N. agassizii (Macpherson 1988 a); the main spines on the walking legs are short or reduced to small granules, sparsely distributed in N. asperrimus (see Fig. 3 B) vs. several long spines on the posterior and dorsal margin of the merus of all walking legs in N. agassizii, especially on the third leg, which remain well developed, even in large specimens (CL above 139 mm) (See Smith 1882, pl. I fig. 1; Takeda 1983: 106; Macpherson 1988 a: 36, fig. 15 A; Lima et al. 2023, fig. 2 A – B). On the other hand, we must consider the sexual dimorphism present in Lithodidae: males show abdominal symmetry, robust and unequal chelipeds, and proportionally longer pereopods. Females exhibit abdominal asymmetry, subequal chelipeds and shorter pereopods compared to males (Ahyong 2010). Barnard (1950), comparing males and females of N. asperrimus, indicated that the spinulation of the chelipeds and walking legs is more densely distributed in females (vs. less densely distributed in males); the dactylus of the walking legs is rounded in crosssection females (vs. flattened, with some lateral expansion in males); and there is one more prominent spine on the lower outer surface of the ischium of the third and fourth walking legs in females (vs. a less prominent spine in males). According to Macpherson (1888 a), in adult specimens of N. agassizii, the morphological differences between the sexes are: the third walking legs are usually equal to or less than three times the carapace length in females (vs. more than three times carapace length in males), and the merus of the third walking leg is proportionally shorter than the carapace length in females (vs. merus longer than carapace length in males) (see Table 2). The development of spines in Lithodidae are highly variable throughout their life stages, being larger and more densely distributed on the carapace, chelipeds and walking legs in juveniles stages, while in adults the spines are proportionally shorter, sometimes reduced to tubercles (Ahyong 2010). In juvenile specimens, taxonomic separation of N. asperrimus and N. agassizii is very difficult due to their morphological similarity (e. g., high density and length of spines in carapace, chelipeds, and walking legs), resulting in a knowledge gap for the taxonomic identification of young individuals. Macpherson (1988 a, fig. 16 D) gave a brief morphological characterization of juveniles of N. asperrimus, and subsequently, Alves-Júnior et al. (2019) and Lima et al. (2023) provided morphological data of juveniles specimens of N. agassizii. However, the main distinguishing characteristics between juveniles of N. asperrimus and N. agassizii are still unknown, which may lead to misidentification of both species in their juvenile stages.	en	Martins, Déborah Elena Galvão, Alves-Júnior, Flavio De Almeida, Cintra, Israel Hidenburgo Aniceto, Bentes, Bianca (2026): First report of the king crab Neolithodes asperrimus Barnard, 1947 (Crustacea: Lithodidae) from the Brazilian Amazon continental slope. Zootaxa 5792 (3): 573-580, DOI: 10.11646/zootaxa.5792.3.8, URL: https://doi.org/10.11646/zootaxa.5792.3.8
