taxonID	type	description	language	source
472EA840E1436339EA24A79CFB970CCC.taxon	description	(Figs 1 - 7) urn: lsid: zoobank. org: act: 2 D 4420 B 0 - C 565 - 4752 - 82 B 4 - BED 197801 D 67	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	materials_examined	TYPE MATERIAL. — Holotype. Dominican Republic • ♂ (CL 2.9 mm); PeÑon ;; 15. XI. 2024; in the sponge Agelas dispar on a coral reef; K. M. Hultgren and S. C. Chak (DR 24 - 5417); FLMNH UF Arthropoda 74183. Allotype. Dominican Republic • 1 ♀ queen (CL 4.6 mm); PeÑon; 15. XI. 2024; in the sponge Hyrtios sp. on a coral reef; K. M. Hultgren and S. C. Chak (DR 24 - 5501); FLMNH UF Arthropoda 74182. Paratypes. Dominican Republic • 1 ♂ (CL 3.3 mm); same data as the holotype (DR 24 - 5420); MNHN-IU- 2025 - 167 • 1 ♂ (CL 3.1 mm); same collection data as the holotype (DR 24 - 5312); GenBank 16 S: PX 552077; FLMNH UF Arthropoda 74183. Puerto Rico • 1 ♂ (CL 3.1); Deep Shelf Reef; 15. III. 2024; in the sponge Agelas dispar on a coral reef; K. M. Hultgren and S. C. Chak (PR 24 - 4803); GenBank COI: PX 572955, 16 S: PX 552075; FLMNH UF Arthropoda 74185. OTHER MATERIAL EXAMINED. — Dominican Republic • 5 ♂ (CL 2.28 - 3.49 mm); Dominicus Reef; K. M. Hultgren and S. C. Chak; 13. XI. 2024; in the sponge Hyrtios sp.; (DR 24 - 402); DU • 6 ♂ (CL 2.34 - 3.48 mm); PeÑon; K. M. Hultgren and S. C. Chak; 15. XI. 2024; in the sponge Ham sponge (DR 24 - 5507); DU • 5 ♂ (CL 2.03 - 3.17 mm); PeÑon; K. M. Hultgren and S. C. Chak; 15. XI. 2024; in the sponge Hyrtios sp. (DR 24 - 6001); DU • 5 ♂ (CL 3.09 - 3.39 mm); Tortuga; K. M. Hultgren and S. C. Chak; 15. XI. 2024; in the sponge Hyrtios sp. (DR 24 - 7102); DU • 4 ♂ (CL 2.72 - 3.17 mm); Dominicus Reef; K. M. Hultgren and S. C. Chak; 13. XI. 2024; in the sponge Hyrtios sp. (DR 24 - 902); DU. Puerto Rico • 1 ♀ queen (CL 4.04 mm); Deep Shelf Reef (PR 24 - 4801); DU • 12 ♂ (CL 1.86 - 2.7 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas dispar (PR 24 - 4802); DU • 3 ♂ (CL 2.18 - 2.8 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas dispar (PR 24 - 4901); DU • 3 ♂ (CL 2.69 - 2.91 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas clathrodes (PR 24 - 5101); DU • 4 ♂ (CL 2.83 - 2.98 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas clathrodes (PR 24 - 5202); DU • 1 ♀ queen (CL 3.3 mm); Deep Shelf Reef (PR 24 - 5401); DU • 7 ♂ (CL 1.9 - 2.89 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas clathrodes (PR 24 - 5412); DU • 1 ♀ queen (CL 3.27 mm); (PR 24 - 6201); DU • 6 ♂ (CL 1.95 - 2.69 mm); Deep Shelf Reef; K. M. Hultgren and S. C. Chak; 15. III. 2024; in the sponge Agelas dispar (PR 24 - 6202); DU.	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	etymology	ETYMOLOGY. — This species is named after Idelisa Bonnelly de Calventi, a marine biologist from the Dominican Republic, often referred to as the mother of marine conservation in the Caribbean region, and the founder of the Dominican Foundation for Marine Research (FUNDEMAR) which helped facilitate our field work.	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	distribution	DISTRIBUTION. — Western Atlantic: Dominican Republic and Puerto Rico (localities within).	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	materials_examined	COMPARATIVE MATERIAL. — Synalpheus rathbunae: Panama (West Atlantic) • 1 ♂; Bocas del Toro; K. M. Hultgren and J. E. Duffy; 9. XI. 2007; in the sponge Neopetrosia rosariensis (Zea & Rützler, 1983); CL 2.6 mm; P 07 - 6203; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 28. II. 2008; in the sponge N. rosariensis; P 08 - 11507 - 03; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 9. XI. 2007; in the sponge N. rosariensis; P 07 - 5801; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 9. XI. 2007; in the sponge N. rosariensis; P 07 - 5303 - 2; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 28. II. 2008; in the sponge N. rosariensis; P 08 - 6801 - 2; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 28. II. 2008; in the sponge N. rosariensis; P 08 - 7701 - 2; DU • 1 ♂; Bocas del Toro; K. M. Hultgren; 28. II. 2008; in the sponge N. rosariensis; P 08 - 11102 - 3; DU • 2 ♂; Bocas del Toro; K. M. Hultgren and J. E. Duffy; 9. XI. 2007; in the sponge N. rosariensis; CL 2.7 mm; P 07 - 6402; GenBank COI: MZ 323465; 16 S: PX 438786; DU. Synalpheus filidigitus: Panama (West Atlantic) • 1 ♂; Bocas del Toro; K. M. Hultgren; 22. II. 2008; in the sponge Neopetrosia cf. proxima (Duchassaing & Michelotti, 1864); P 08 - 14601 - 31; DU. Belize • 1 ♂; Sand Bores; K. M. Hultgren and K. S. Macdonald; 27. VII. 2009; in the sponge N. cf. proxima; CBC 09 - 4203 - 2; DU • 2 ♂; Sand Bores; K. M. Hultgren and K. S. Macdonald; 27. VII. 2009; in the sponge N. cf. proxima; CBC 09 - 7604; DU.	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	description	DESCRIPTION (BASED ON ALL MATERIAL EXAMINED) Body Subcylindrical; carapace smooth, sparsely setose, pterygostomian corner with broad acute angle, posterior portion with distinct cardiac notch. Frontal margin (Figs 1 A, B; 3 C) Rostrum narrower than orbital hoods, about as long as orbital hoods, and separated from hoods by deep sinus. Orbital hoods hoof-shaped. Stylocerite broad, with bluntly acute tip, distinctly shorter than first segment of antennular peduncle. First antennular segment with two basal ventral processes. Basicerite with strong, sharp spine on dorsal margin; length of longer lateral spine of basicerite variable, nearly reaching or slightly exceeding 2 nd segment of antennular peduncle. Lateral spine of basicerite about 50 - 80 % length of scaphocerite. Scaphocerite without blade, with robust lateral spine, reaching or overreaching distal end of 3 rd article of antennular peduncle. Mouthparts not dissected, apparently typical externally for the genus. Appendages Major pereopod 1 (major chela; Figs 1 C-E; 3 A; Supplement SA 1) massive, fingers shorter than half length of palm, fixed finger shorter than dactyl. Palm of chela with distal, superior margin produced into cone-shaped projection, pointing forward or slightly upwards, without an acute spine. Minor pereopod 1 (minor chela; Figs 1 F-G; 2 J) with palm less than two times longer than high, fingers shorter than palm; dactyl (moveable finger) with flexor margin concave, blade-like, without accessory teeth; conspicuous dorsal brush of setae on extensor side of dactyl; fixed finger mildly concave, with no hint of subdistal tooth. Pereopod 2 (Fig. 2 A) with carpus 4 - segmented, subequal in length relative to merus. Approximate length ratios for carpal articles of the second pereopod: 1: 0.3: 0.3: 0.6 (from proximal segment to distal segment). Pereopod 3 (Fig. 2 B) with biunguiculate dactyl, with flexor unguis about equal (in thickness and length) than extensor unguis, propodus with 4 - 5 mobile spines on flexor margin and one pair of spines on distal end; carpus with one distal spine on flexor margin; merus without spines on flexor margin. Pereopod 4 (Fig. 2 C) similar to 3 rd. Pereopod 5 (Fig. 2 D; 3 H) similar to 4 th, but without distal spine on carpus, and with five transverse combs of stiff setae on flexor margin of propodus. Maxilliped 3 (Fig. 2 E) with distal circlet of spines on distal segment, lacking ventrodistal spine on antepenultimate segment. Abdomen Pleuron 1 of male (Figs 2 G, I; 3 B) narrow, with anterior corner rounded, posterior corner produced into long slightly hooked projection, with subacute or slightly rounded tip; pleura 2 - 5 also narrow, with posterior distal corners of pleura 2 - 5 forming extended, triangular projections. Pleuron 1 of female (Fig. 2 H) rounded anteriorly and posteriorly, posterior corners of pleura 2 - 5 rounded. Telson (Fig. 2 F, K; Supplement SA 1) with mesial pair of distal telson spines thicker and longer than lateral spines, posterior corners adjacent to distal spines obtuse, distance between distal spines 10 - 30 % width of distal margin. Dorsal telson spines variable, with many individuals (non-ovigerous workers and queens) missing 1 - 3 dorsal telson spines (see Morphological variations). Uropods (Fig. 2 F) with 1 - 2 marginal fixed teeth on exopod anterior to moveable spine, fixed anterior teeth distinctly removed from fixed tooth. Color Nondescript, translucent body with distal tips of chelae tinged orange; ovaries and embryos light yellowish-green (Fig. 6). First larva Newly hatched larvae obtained from the allotype, DR 24 - 5501, being crawling megalopae (direct development), similar to direct-developing larvae described for many other eusocial species (Hultgren et al. 2021). Morphological variation Several female queens from Puerto Rico had two minor chelae, instead of a minor chela and a major chela (e. g., Fig. 5). One of the colonies in the Dominican Republic (DR 24 5303 - 5305) had three workers with two minor chelae. These workers had pleura that were typical of males (e. g., Fig. 2 I). Many of the male workers (approximately 58 % of the 67 non-ovigerous workers surveyed, from 13 different colonies, including the holotype Fig. 2 F) and female queens (33 % of the six queens surveyed) had an atypical number of dorsal telson spines – one, two, or three spines (instead of the typical four).	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
472EA840E1436339EA24A79CFB970CCC.taxon	biology_ecology	Ecology and colony size (Table 3) In both the Dominican Republic and Puerto Rico, we have found S. idelisae n. sp. living within sponges of the genus Agelas (A. dispar and A. clathrodes), and in the Dominican Republic it was also commonly inhabiting the sponge Hyrtios sp. In Puerto Rico, all colonies of S. idelisae n. sp. were found in Agelas dispar and A. clathrodes only from deep sites (23 m depth); Agelas host sponges were collected at shallower depths (6 - 12 m depth), but never contained S. idelisae n. sp. In the Dominican Republic, S. idelisae n. sp. was found in sponges at shallower depths (12 - 15.5 m). Colony size ranged from 8 - 67 individuals (median = 28 individuals), but we did not find queens in every colony, suggesting many colonies may be incompletely sampled. In colonies with queens, there was only a single queen present.	en	Hultgren, Kristin M., Claire, Kristina Camia, Bailey, Claire (2026): A new eusocial species of snapping shrimp, Synalpheus idelisae n. sp. (Decapoda, Alpheidae), with a review of caste differentiation in eusocial shrimp. Zoosystema 48 (20): 623-638, DOI: 10.5252/zoosystema2026v48a20
