taxonID	type	description	language	source
03A387BCFFB5FF97FDE7C467FCB47034.taxon	materials_examined	The material examined is deposited in the Zoological Survey of India, Western Regional Centre, Pune, India (ZSI-WRC), while the comparative material was from the Crustacea Section of the Zoological Survey of India, Kolkata, India (ZSIK). The specimens were identified using the key of Pati et al. (2019). The terminologies and measurement methods of the carapace are after Ng (1988). The following abbreviations are used: CW, width of carapace; CL, length of carapace; coll., collector; G 1, male first gonopod; G 2, male second gonopod.	en	Mohapatra, Sameer Kumar Pati Swarup Ranjan Mohanty Anil (2023): First record of a potamid crab (Decapoda: Brachyura) from Odisha State, India. Nauplius (e 2023020) 31: 1-7, DOI: 10.1590/2358-2936e2023020
03A387BCFFB4FF95FF0CC5D9FAEB7796.taxon	description	(Fig. 1)	en	Mohapatra, Sameer Kumar Pati Swarup Ranjan Mohanty Anil (2023): First record of a potamid crab (Decapoda: Brachyura) from Odisha State, India. Nauplius (e 2023020) 31: 1-7, DOI: 10.1590/2358-2936e2023020
03A387BCFFB4FF95FF0CC5D9FAEB7796.taxon	materials_examined	Material examined. 2 males (29.97 × 24.13 mm, 26.34 × 19.43 mm), 2 females (23.94 × 19.45 mm, 23.24 × 18.99 mm), ZSI-WRC C. 1920, India, Odisha State, Jagatsinghpur District, Banikunda, 20.332 86.155, altitude 12 m, 23 July 2017, S. R. Mohanty coll.; 5 males (22.58 × 17.90 mm, 22.35 × 18.43 mm, 22.34 × 18.18 mm, 21.50 × 17.64 mm, 20.15 × 16.65 mm), ZSI-WRC C. 1921, same data as preceding collection. Comparative material. Syntype male (29.2 × 22.0 mm), ZSIK 4069 / 4, India, Bihar State, Purnia District, Purnia (= Purneah) [~ 25.780 87.470], altitude ~ 42 m, no date, museum collector. Diagnosis. Carapace subhexagonal, relatively broad (CW / CL = 1.3 – 1.4); anterolateral margins each with 3 prominent epibranchial teeth; first epibranchial tooth distinctly broader than second- and third epibranchial teeth, directed anteriorly, basally broad, tip acute, separated from external orbital tooth by distinct cleft; second epibranchial tooth directed laterally, basally narrow, tip acute; third epibranchial tooth directed laterally, basally broad, tip acute; posterolateral margins almost straight, converging; postorbital cristae relatively long, extending beyond level of mid supraorbital margin; external orbital tooth broadly triangular (Fig. 1 A). Major cheliped carpus with well-developed, acute inner distal tooth (Fig. 1 A). G 1 with flexible zone strongly reduced; terminal segment relatively stout, subcylindrical, relatively long, approximately 0.4 times length of subterminal segment; subterminal segment with inner (mesial) margin straight just below flexible zone, outer (lateral) margin sharply raised in proximal half to distinct shelf or hump (Fig. 1 B – D). G 2 longer than G 1, approximately 1.1 – 1.2 times length of G 1; distal segment relatively short, approximately 0.5 times length of basal segment (Fig. 1 E). Ecological notes. Specimens of A. martensi were collected from shallow burrows (<0.3 m deep) along the margins of a turbid water channel adjacent to rice and sugarcane fields (Fig. 2). The margins of the water channel have a profuse growth of Kans Grass (Saccharum spontaneum L. of the family Poaceae). At the collection site, these crabs are very common and active during the rainy season (July-September) only. Geographical distribution. Acanthopotamon martensi has a wider distribution in the northern part of the Indian subcontinent, with confirmed records from Bangladesh, India (Bihar, Haryana, Punjab, Uttar Pradesh, Uttarakhand, and West Bengal States), Nepal, and Pakistan (see Pati et al., 2019) (Fig. 3). Until now, the distribution of A. martensi was limited to the ‘ Ganges Delta and Plain’ and the ‘ Lower and Middle Indus’ freshwater ecoregions (Fig. 3) (Abell et al., 2008; Pati et al., 2019). The present record of A. martensi from Odisha confirms its occurrence in the ‘ Northern Deccan Plateau’ freshwater ecoregion (Fig. 3) (Abell et al., 2008). Remarks. According to Shih et al. (2009), potamid crabs are not known from the main Indian subcontinent south of the Ganges River. They also noted that strong competition from the dominating gecarcinucid crabs in the Indian Peninsula may have restricted the southward extension of potamids. The present record of A. martensi from Odisha, however, represents the southernmost record of the family Potamidae in the Indian subcontinent. In fact, A. martensi is one of two potamid species that is known from the south of the Ganges, the other species being Acanthopotamon panningi (Bott, 1966) (Fig. 3; see Bott, 1966; Pati et al., 2019: fig. 1). Counting the present record of A. martensi, five species of freshwater crabs are now known from Odisha State. Odisha possesses four major physiographic regions: 1) Eastern Coastal Plains, mainly formed by the deltas of six major rivers; 2) Northern Plateau, an extension of Chota Nagpur Plateau; 3) the Central Tract, consisting of plateaus, hills, uplands and valleys; and 4) Eastern Ghats (Tikader and Chhotani, 1987). All these regions provide an array of habitats for freshwater crabs. Most of these regions, however, have been underexplored for freshwater crabs. The present new record of A. martensi and the description of a new species by Pati and Sharma (2012) indicate that there may be more freshwater crab taxa yet to be recognized from the state. More systematic surveys on freshwater crabs, therefore, need to be conducted in Odisha.	en	Mohapatra, Sameer Kumar Pati Swarup Ranjan Mohanty Anil (2023): First record of a potamid crab (Decapoda: Brachyura) from Odisha State, India. Nauplius (e 2023020) 31: 1-7, DOI: 10.1590/2358-2936e2023020
