taxonID	type	description	language	source
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	description	Figures 1 – 3	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	materials_examined	Material examined Holotype: Length 8.79 mm, Width 0.31 mm (ZSI / EBRC / An- 15937), Chilika Lagoon, southern sector (19 ° 36 ʹ 14.16 ” N, 85 ° 11 ʹ 33.14 ” E), Odisha, India, 30 / 06 / 2023, Coll. Amita Kumari Choudhury. Paratypes (02 numbers): ZSI / EBRC / An- 15938, Length- 14.76 mm, Width- 0.64 mm, incomplete specimen, ZSI / EBRC / An- 15939, Length- 10.12 mm, Width- 0.35 mm, incomplete specimen. Other materials: 03 individuals, length (8.01 – 17 mm), width (0.28 – 0.59 mm) (004. MSR / BoL- 24); same data as holotype.	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	etymology	Etymology The species is named after the site of its collection which is the Chilika Lagoon.	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	biology_ecology	Habitat In soft mud sand, depth 2.6 m, water temperature 30 ° C, salinity 20 PSU.	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	diagnosis	Diagnosis Median antenna cylindrical, widest at the base with a tapered blunt end, branchiae anteriorly short, gradually increasing in size and elongated in last 4 – 5 chaetigers, modified neurochaetae distally strongly curved with a single long arista.	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	description	Description Based on holotype, length: 8.79 mm, width: 0.31 mm. Holotype complete with 101 chaetigers, body length 8.79 mm, width 0.31 mm; paratypes incomplete with 78 – 88 chaetigers, 10.12 – 14.76 mm long and 0.35 – 0.64 mm wide. Body wide, dorsoventrally flattened in branchial region, cylindrical in post-branchial region (Figure 3 A). Prostomium triangular, width 2 × times the length, distally rounded, with reddish pigment spots present along the anterior and lateral prostomial margin. Eye absent. Nuchal organs are a pair of oblique, deep slits. Median antennae are well-developed with central insertion, cylindrical, elongated, widest at the base and tapering to a blunt end, extending up to chaetiger 2 (Fig 1 A, 3 B). Twenty-three pairs of branchiae are present on chaetiger 4 – 26. Branchiae arranged on dorsum, basally inflated without a ciliary band. Anterior branchiae are foliaceous, blunt-tipped, gradually increase in size and overlap along the midline of the body. Posterior-most (in last 4 – 5 chaetigers) are elongated, cirriform, blunt-tipped and longer than the anterior ones (Fig 1 A, 3 B). The first two notopodial postchaetal lobes are short and round (Figure 1 B). Notopodial postchaetal lobes gradually increase from chaetiger 3, progressively longer in the branchial region to long, thin, filiform in the posterior region (Figure 1 C). Neuropodial postchaetal lobes are absent. Inter-ramal papilla present till branchial region. Chaetae well-developed. Notochaetae all slender capillaries (Figure 2 A). Notochaetae of the anterior region are comparatively thicker and longer than the postbranchial region. Neurochaetae includes slender capillary and modified chaetae starting from chaetiger 33. Modified neurochaetae distally strongly curved with a terminal long arista. Up to 6 – 8 modified chaetae per neuropodium (Fig. 2 b, 3 c). Mid-dorsal transversal line of prebranchial and branchial chaetigers without ciliary band. Pygidium, rounded with four reddish pigment spots and two anal cirri of similar size (Figure 2 C).	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
03BE87DAAD429664AD24FA5FFCF4FDD1.taxon	discussion	Remarks According to WoRMS database, a total of 26 species belong to the genus Aricidea (Acmira) (Read and Fauchald 2024). Further, Aricidea elongata Imajima 1973 and Aricidea rosea; Reish, 1968 which are not included under the subgenus Acmira, also possess hook and terminal distal arista in the posterior modified neuropodial region. Including these two species, the total species number under the subgenus leads to 28. A comparative table of the morphological characteristics of the species of the genus Aricidea (Acmira) is provided in Table 1. Aricidea (Acmira) chilikensis sp. n. can be distinguished from other members of the subgenus by the shape of the median antenna, structure and pattern of the branchia, and modified neurochaetae. Among the 28 species, 18 species possess single or multiple terminal distal aristae in the modified posterior neuropodial region. Fifteen species, Aricidea (Acmira) bbkingi Barroso, Paiva & Ranauro, 2020, A. (A.) catherinae, Aricidea (Acmira) elongata Imajima, 1973, Aricidea (Acmira) filamentosa Barroso, Paiva & Ranauro, 2020, Aricidea (Acmira) finitima Strelzov, 1973, Aricidea (Acmira) katzmanni Erdoğan-Dereli & Çinar, 2020, Aricidea (Acmira) laubieri Hartley, 1981, A. (A.) lopezi, Aricidea (Acmira) meridionalis Laubier & Ramos, 1974, Aricidea (Acmira) mirifica Strelzov, 1973, Aricidea (Acmira) philbinae Brown, 1976, Aricidea (Acmira) pseudoassimilis Erdoğan-Dereli & Çinar, 2020, Aricidea (Acmira) rosea Reish, 1968, Aricidea (Acmira) rubra Hartman, 1963 and Aricidea (Acmira) taylori Pettibone, 1965 have single terminal distal arista similar to A. (A.) chilikensis sp. n. Amongst the above 15 species, majority have posterior branchiae that are relatively longer than anterior branchiae, however, the last few pairs are equal or short in most species, whereas in A. (A.) chilikensis sp. n., the last pairs are the longest. Aricidea (Acmira) chilikensis sp. n. is characterised by branchiae that are shorter on anterior chaetigers and that gradually increase in size posteriorly, with posterior-most branchiae relatively elongated and narrow. In A. (A.) bbkingi, A. (A.) catherinae, A. (A.) elongata, and A. (A.) pseudoassimilis, the branchiae located at the posterior end are not elongated, indicating a more uniform length throughout. In contrast, A. (A.) philbinae exhibits elongated branchiae in the anterior region, making it distinctive. In species such as A. (A.) laubieri, the posterior pair of branchiae are smaller, while in A. (A.) filamentosa, A. (A.) finitima, and A. (A.) katzmanni, only the last two pairs of branchiae are shorter than the others, giving these species a characteristic appearance. In A. (A.) lopezi, branchiae are present from chaetiger 4 to 53 (while in A. (A.) chilikensis sp. n., they are present from chaetiger 4 to 26). (Continued) Similarly, A. (A.) mirifica and A. (A.) rosea possess only a single short pair of branchiae located at the very end of the body. A. (A.) rubra has antennae that end in a sharply pointed tip (A. (A.) chilikensis sp. n., has cylindrical, elongated antennae that are widest at the base and taper to a blunt end) and possesses up to 30 pairs of branchiae (23 pairs in A. (A.) chilikensis sp. n., In A. (A.) taylori, the branchiae are ciliated except at the distal tip, while cilia are absent in A. (A.) chilikensis sp. n. In addition, the median antenna of A. (A.) chilikensis sp. n. is widest at the base tapering to a blunt end. Among the above 15 species, A. (A.) meridionalis shows antenna and branchial characters similar to A. (A.) chilikensis sp. n. Aricidea (Acmira) chilikensis sp. n. differs from A. (A.) meridionalis by lacking a ciliary band on both sides of the branchia and on the mid-dorsal transversal line of branchial and prebranchial chaetigers (vs. present in A. (A.) meridionalis). Further, the terminal and subterminal region of modified neurochaetae display small hairs which are absent in A. (A.) chilikensis sp. n.	en	Choudhury, Amita Kumari, Dutta, Joydeep, Patro, Shesdev, Rastogi, Gurdeep (2025): A new species of the genus Aricidea (Acmira) Hartley, 1981 (Polychaeta: Paraonidae) from Chilika Lagoon, east coast of India. Journal of Natural History 59 (1 - 4): 45-55, DOI: 10.1080/00222933.2024.2439620, URL: https://doi.org/10.1080/00222933.2024.2439620
