A new Callichirus ghost shrimp species from the southwestern Atlantic, long confounded with C. major (Say, 1818) (Decapoda: Axiidea: Callichiridae) Author Hernáez, Patricio Author Miranda, Marcel S. Author Rio, Juliana P. P. Author Pinheiro, Marcelo A. A. text Journal of Natural History 2022 2022-07-14 56 9 - 12 533 563 http://dx.doi.org/10.1080/00222933.2022.2067016 journal article 125513 10.1080/00222933.2022.2067016 ffc96fd8-8dba-4891-ac17-9c160719d50a 1464-5262 7012462 29450E54-130A-4838-B923-F9676609DB3A Callichirus corruptus sp. nov. ( Figures 1a , 2 , 3 , 4 , 5 , 8a , 9b , 10b, c ) Callianassa ( Callichirus ) major Rodrigues 1971: 192 , Figure 1 –20 [not Callichirus major ( Say, 1818 ) ]. Callichirus major Rodrigues 1976: 85 , figs 1–35, 1985: 195, Figure 1 –30; Rodrigues and Höld 1990: 48 ; Borzone and Souza 1996: 67 ; Souza and Borzone 1996: 553 ; Rodrigues and Shimizu 1997: 155 , Figure 1 ; Souza et al. 1998: 151 ; Coelho and Rodrigues 2001: 1447 , figs 13–21; Botter-Carvalho et al. 2002: 97 ; Souza and Borzone 2003: 625 ; Botter-Carvalho et al. 2007: 508 ; Peiró and Mantelatto 2011: 5 ; Peiró et al. 2011: 261; Botter-Carvalho et al. 2012: 89 ; Dworschak et al. 2012: 151 , fig. 69.29a,b, 69.31t ; Alves-Junior et al. 2014a: 109 ; Alves-Junior et al. 2014b: 13 ; Peiró et al. 2014: 294 ; Pachelle et al. 2016: 20 ; Peiró and Mantelatto 2016: 103 , pl. 1; Alves-Junior et al. 2018: 166 ; Hernáez et al. 2018: 97 ; Rosa et al. 2018: 1 ; Souza et al. 2018: 1 ; Hernáez et al. 2019: 1 , Figure 1 ; Rio et al. 2019: 1 , Figure 2 ; Hernáez et al. 2020: 1 , fig. 4c; Laurino et al. 2020: 1 [not Callichirus major ( Say, 1818 ) ]; Moschetto et al. 2020: 1 . Table 2. Estimation of evolutionary divergence over sequence pairs from the portion of the mitochondrial 16S rDNA with ~510 bp.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 Callichirus corruptus sp. nov.
2 Callichirus sp. 2 0.03
3 Callichirus sp. 1 0.05 0.05
4 Callichirus major 0.05 0.06 0.06
5 Callichirus seilacheri ? 0.08 0.09 0.09 0.09
6 Callichirus garthi 0.09 0.09 0.10 0.10 0.06
7 Callichirus islagrande 0.09 0.08 0.09 0.09 0.05 0.05
8 Callichirus seilacheri 0.12 0.11 0.12 0.11 0.07 0.06 0.06
9 Audacallichirus mirim 0.19 0.17 0.19 0.19 0.20 0.19 0.19 0.21
10 Filhollianassa ceramica 0.19 0.19 0.18 0.20 0.21 0.19 0.19 0.22 0.22
11 Filhollianassa filholi 0.20 0.18 0.18 0.20 0.21 0.19 0.19 0.22 0.22 0.05
12 Lepidophthalmus siriboia 0.21 0.19 0.20 0.20 0.21 0.20 0.21 0.23 0.16 0.22 0.22
13 Biffarius biformis 0.23 0.21 0.22 0.23 0.23 0.22 0.22 0.24 0.22 0.19 0.18 0.24
14 Pugnatrypaea sp. 0.24 0.23 0.22 0.23 0.22 0.25 0.23 0.23 0.25 0.20 0.22 0.26 0.19
15 Neocallichirus guassutinga 0.25 0.24 0.23 0.27 0.26 0.26 0.26 0.28 0.25 0.27 0.28 0.29 0.31 0.32
16 Aqaballianassa aqbaensis 0.26 0.25 0.26 0.27 0.29 0.25 0.26 0.28 0.28 0.24 0.22 0.29 0.23 0.23 0.37
Figure 2. Callichirus corruptus sp. nov. a–d, holotype, male (cl: 18.8 mm), MZUSP 41251; e, paratype, male (cl: 18.6 mm), MZUSP 41253. a, body, lateral view; b, carapace and cephalic appendages, lateral view (arrows indicate branchiostegal lobe and emargination on central part of carapace); c, anterior part of carapace and cephalic appendages, dorsal view; d, basal part of antennal peduncle, dorsal view (setae omitted; arrow indicates scaphocerite); e, right third maxilliped, external surface. Scale bars: a = 1 cm; b, c = 2 mm; d = 1 mm; e = 4 mm. Callichirus sp. Strasser and Felder 1999a: 865 . Callichirus macrotelsonis Peiró 2012: 58 , figs 3–7 [ nomen nudum ]. Callichirus brasiliensis Rio 2018: 20 , figs 1a, 2a, 3a, 3b, 4a [ nomen nudum ].
Type material Brazil . São Paulo : holotype , male, cl: 18.8 mm ( MZUSP 41251 ), Praia do Gonzaga , 23.970° S , 46.334°W , lower intertidal, Santos, P . Hernáez coll ., 1 September 2016 . Paratypes : 1 female , cl: 20.4 mm ( MZUSP 41252 ), 4 males (one dissected), cl: 15.4–19.4 mm , and 4 females , cl: 16.4–22.2 mm (2 ovigerous females) ( MZUSP 41253 ), same data as holotype . Non-type material Figure 3. Callichirus corruptus sp. nov. a, c, holotype, male (cl: 18.8 mm), MZUSP 41251; b, d, paratype, female (cl: 20.4 mm), MZUSP 41252. a, c, male major and minor chelipeds, respectively, lateral view; b, d, female major and minor chelipeds, respectively, lateral view. Scale bars: 1 cm. Brazil . Pará : 8 males , cl: 10.1–18.3 mm , and 15 females , cl: 10.4–19.2 mm , Praia do Crispim , 0.583°S , 47.651°W , lower intertidal, Marapanim , coll . P . Hernáez , 9 July 2017 ( MZUSP 38995 ); 8 males , cl: 13.7–19.6 mm , and 11 females , cl: 10.5–21.2 mm , Praia de Ajuruteua , 0.828°S , 46.606°W , lower intertidal, Bragança, P . Hernáez coll ., 7 July 2017 ( MZUSP 38993 ) . Maranhão : 10 males , cl: 10.8–17.6 mm , and 15 females , cl: 12.5– 19.8 mm , Praia Olho d´agua, 2.479°S , 44.231°W , lower intertidal, São Luis, P . Hernáez coll ., 6 July 2017 ( MZUSP 38994 ); 1 male , cl 12.4 mm , and 2 females , cl: 15.6–18.7 mm , Praia de Tutoia , 2.761°S , 42.263°W , lower intertidal, Tutóia, P . Hernáez coll ., 5 July 2017 ( MZUSP 39001 ) . Piauí : 9 males , cl: 9.6–15.6 mm , and 14 females , cl: 10.2–17.7 mm , Praia da Atalaia , 2.889°S , 41.628°W , lower intertidal, Luis Correia, P . Hernáez coll ., 3 July 2017 ( MZUSP 38998 ) . Ceará : 2 females , cl: 5.8–10.4 mm , close to the marine lighthouse, 2.876°S , 40.923°W , lower intertidal, Camocim, P . Hernáez coll ., 3 July 2017 ( MZUSP 39006 ) . Rio Grande do Norte : 22 males , cl: 5.6–12.8 mm , and 19 females , cl: 7.6–13.3 mm , Praia do Pirangi , 5.974°S , 35.124°W , lower intertidal, Pirangi, P . Hernáez coll ., 11 June 2016 ( MZUSP 39011 ) . Pernambuco : 1 male , cl: 10.5 mm , and 4 females , cl: 13.9–16.1 mm , Praia de Baixa Verde , 7.755°S , 34.824°W , lower intertidal, Ilha de Itamaracá, P . Hernáez coll ., 17 June 2016 ( MZUSP 39012 ); 6 males , cl: 7.9–15.9 mm , and 5 females , cl: 7.8–15.3 mm , Praia Piedade , 8.167°S , 34.913°W , lower intertidal, Recife, P . Hernáez coll ., 10 June 2016 ( MZUSP 39013 ) . Alagoas : 15 males , cl: 9.0–16.0 mm, and 14 females , cl: 12.9–17.7 mm , Praia do Sobral , 9.673°S , 35.562°W , lower intertidal, Maceió, P . Hernáez coll ., 9 June 2016 ( MZUSP 39014 ) . Sergipe : 9 males , cl: 11.5–15.8 mm , and 18 females , cl: 10.3–18.0 mm, Praia Aruana , 11.014°S , 37.064°W , lower intertidal, Aracajú, P . Hernáez coll ., 8 June 2016 ( MZUSP 39016 ) . Bahia : 16 males , cl: 12.6–15.7 mm , and 16 females , cl: 11.8–14.7 mm , Praia Malvinas , 18.080°S , 39.543°W , lower intertidal, Mucuri, P . Hernáez coll ., 20 June 2016 ( MZUSP 39022 ) . Espirito Santo : 15 males , cl: 7.8–12.5 mm , and 11 females , cl: 6.8– 12.2 mm , Praia de Piúma , 20.844°S , 40.734°W , lower intertidal, Piúma, P . Hernáez coll ., 3 June 2016 ( MZUSP 39023 ) . São Paulo : 14 males , cl: 5.7–11.9 mm , and 8 females , cl: 7.4– 11.5 mm , Praia de Barequeçaba , 23.828°S , 45.434°W , lower intertidal, Barequeçaba , São Paulo , P . Hernáez coll ., 2 June 2016 ( MZUSP 39028 ); 28 males , cl: 10.1–19.1 mm , and 64 females , cl: 8.0– 23.2 mm , Praia do Gonzaga , 23.970°S , 46.334°W , lower intertidal, Santos, P . Hernáez coll ., 1 September 2016 ( MZUSP 39027 ); 3 males , cl: 8.6–15.5 mm , and 3 females , cl: 7.9–8.3 mm , Cibratel , 24.201°S , 46.813°W , lower intertidal, Itanhaém, P . Hernáez coll ., 12 August 2016 ( MZUSP 39026 ); 3 males , cl: 7.3–10.8 mm , and 3 females , cl: 7.4–14.4 mm , Rio Peruíbe , 24.330°S , 47.000°W , estuary, Peruíbe, P . Hernáez coll ., 1 September 2016 ( MZUSP 39025 ); 8 males , cl: 6.4–18.7 mm , and 4 females , cl: 12.6– 15.9 mm , Praia Ilha Comprida , 24.756°S , 47.559°W , lower intertidal, Ilha Comprida, P . Hernáez and J . Rio coll ., 1 July 2016 ( MZUSP 39029 ) . Paraná : 15 males , cl: 7.9– 16.7 mm , and 22 females , cl: 10.0– 16.4 mm , Praia de Leste , 25.631°S , 48.421°W , lower intertidal, Pontal de Paraná , P . Hernáez and J . Rio coll ., 2 July 2016 ( MZUSP 39037 ) . Santa Catarina : 10 males , cl: 11.0– 16.7 mm , and 27 females , cl: 8.9–22.3 mm , Balneário Camboriú , 26.989°S , 48.629°W , lower intertidal, Camboriú, P . Hernáez and J . Rio coll ., 3 July 2016 ( MZUSP 39039 ) . Figure 4. Callichirus corruptus sp. nov. ; holotype, male (cl: 18.8 mm), MZUSP 41251. a–d, second, third, fourth and fifth pereopods, respectively, lateral view. Scale bars: 2 mm. Figure 5. Callichirus corruptus sp. nov. a, b, d, f, holotype, male (cl: 18.8 mm), MZUSP 41251; c, e, paratype, female (cl: 20.4 mm), MZUSP 41252. a, sixth pleomere, uropods and telson, dorsal view; b, c, male and female first pleopods, respectively, external surface; d, e, male and female second pleopods, respectively, external surface; f, third to fifth pleopods, external surface. Scale bars: a, c, e, f = 2 mm; b, d = 1 mm. Figure 6. Molecular phylogenetic tree represented as maximum likelihood topology of the partial mitochondrial DNA sequence of the 16S rDNA gene to place Callichirus corruptus sp. nov. Nodal support values represent the frequencies observed using 1000 bootstrap pseudo-replicates. Values below 50% are not represented. Figure 7. Callichirus major . a, b, neotype, male (cl 13.2 mm), Indian River, Florida, USA, USNM 228086. c, e, male (cl: 20.6 mm), New River, North Carolina, USA, USNM 266227. d, male (cl: 24.4 mm), Louisiana, Gulf Of Mexico, USA, USNM 79171. f, female (cl: 16.3 mm), Indian River, Florida, USA, USNM 228087. a, carapace front, eyestalks, and antennular and antennal peduncles, dorsal view; b, male major cheliped claw, lateral view; c, d, male second pleopod, external surface; e, male major cheliped claw, lateral view; f, female major cheliped, lateral view. Scale bars: a = 2 mm; b, e, f = 1 cm; c, d = 1 mm. Comparative material examined Callichirus garthi ( Retamal, 1975 ) . Chile : 53 males , cl: 3.8–23.3 mm , and 54 females , cl: 4.3–21.9 mm , Las Machas , 18.437°S , 70.304°W , Arica, P . Hernáez coll ., 27 August 2011 , MUAP-CD 0426/2011; holotype , male, cl: 35 mm , Lenga , 36.75°S , 73.17°W , Concepción, M . A . Retamal coll ., May 1975 ( MZUC-UCCC 7311 ); paratype , male, cl: 30 mm , same site as holotype , March 1974 , coll . M .A . Retamal ( MZUC-UCCC 7313 ); 66 males , cl: 7.6–21.3 mm , and 68 females , cl: 8.6–20.0 mm, Lenga , 36.77°S , 73.172°W , Concepción, P . Hernáez coll ., 9 March 2011 ( MUAPCD 0432 /2011) . Callichirus islagrande ( Schmitt, 1935 ) : USA : Gulf of Mexico : holotype , male, cl: 19 mm , Grand Isle , Louisiana , W .W . Anderson coll ., summer of 1930 ( USNM 69362 ) . Callichirus major ( Say, 1818 ) : USA : North Carolina : 1 male , cl: 20.6 mm , Onslow Bay , 34.606°N , 77.210°W , New River, R .B . Manning and D .B. Bixler coll ., 30 July 1989 ( USNM 266227 ); 1 female , cl: 11.9 mm , Onslow Bay , 34.606°N , 77.210°W , New River, R .B . Manning and D .B. Bixler coll ., 7 August 1990 ( USNM 266232 ) . Georgia : 1 male , cl: 21.2 mm , Tybee Island , 31.999°N , 80.841°W , G .A . Bishop coll ., 1 April 1988 ( USNM 266247 ) . Louisiana : 2 males , cl: 15.0– 24.4 mm , Grand Island , 30.133°N , 89.417°W , Gulf of Mexico, E .R . Willis coll ., 26 June 1939 ( USNM 79171 ) . Texas : 1 ovigerous female, cl: 16.4 mm , Heald Bank , 29.727°N , 93.708°W , Sabine, W .G . Hewatt coll ., 1967 ( USNM 97653 ) . Florida : 2 ovigerous females, cl: 9.7–20.2 mm , Indian River , 27.88°N , 80.457°W , R .B . Manning, W. Lee, M . Schotte and C . King coll ., 20 April 1988 ( USNM 266125 ); 1 female , cl: 21.0 mm, Indian River , 27.636° N , 80.364°W , North Hutchinson Island , Fort Pierce, D .L . Felder and W . Lee coll ., 14 August 1987 , USNM 266118; 1 male , cl: 11.1 mm , Fort Pierce area , 27.472°N , 80.297° W , R .B . Manning coll ., 2 March 1987 ( USNM 266127 ); 1 female , cl: 15.4 mm , Indian River , 27.472°N , 87.297°W , North Hutchinson Island , Fort Pierce, R .B . Manning and W . Lee coll ., 2 March 1987 ( USNM 266126 ); 1 female , cl 16.3 mm , Indian River , 27.183°N , 80.158°W , Seminole Shores, R .B . Manning and L .K. Manning coll ., 7 July 1984 ( USNM 266111 ); 1 female , cl 16.3 mm , Indian River , 27.175°N , 80.173°W , Flat Just Inside Saint Lucie Inlet, R .B . Manning coll ., 11 February 1983 ( USNM 228087 ); topotype, male, cl 13.2 mm , Indian River , 27.171°N , 80.173°W , R .B . Manning coll ., 9 February 1983 ( USNM 228086 ); 1 male , cl 18.6 mm , Lake Worth Inlet , 26.771°N , 80.037°W , Peanut Island, R .B . Manning and D .L. Felder coll ., 11 August 1987 ( USNM 266114 ) . Callichirus aff. major : Colombia : Caribbean coast: 1 male , cl 22.2 mm , La Boquilla , 10.472°N , 75.500°W , Cartagena, R . Lemaitre coll ., 10 August 1980 ( USNM 266208 ); 1 male , cl 13.9 mm , and 1 ovigerous female, cl 13.7 mm , La Boquilla , 10.472°N , 75.500°W , Cartagena, R . Lemaitre coll ., 10 August 1988 ( USNM 266225 ); 1 female , cl 23.6 mm , Castillo Grande , 10.395°N , 75.551°W , Cartagena Bay , Cartagena, R . Lemaitre coll ., 7 July 1988 ( USNM 266211 ) . Callichirus seilacheri ( Bott, 1955 ) : El Salvador : 1 male , cl 16.3 mm , and 1 female , cl 24.1 mm , Los Blancos , topotype, 13.327°N , 88.969°W , P . Hernáez and A . Gamboa-González coll ., 22 July 2013 ( MZUCR 3335–01 ); 1 male , cl 8.4 mm , and 5 females , cl: 9.7–20.2 mm , Los Blancos , topotype, 13.327°N , 88.969°W , P . Hernáez and A . Gamboa-González coll ., 22 July 2013 ( MZUCR 3336–01 ) . Costa Rica : Pacific coast: 15 males , cl: 8.2–14.5 mm , and 16 females , cl: 8.6–14.9 mm , Mata de Limon , 9.92°N , 84.710°W , Puntarenas , P . Hernáez and A . GamboaGonzález coll ., 10 June 2012 ( MZUCR 3337–01 ) . Figure 8. Carapace and cephalic appendages, dorsal view. a, Callichirus corruptus sp. nov. , MZUSP 41251; b, Callichirus garthi , MUAP-CD 0426/2011; c, Callichirus islagrande (courtesy of Nuno Simões); d, Callichirus major , USNM 228086; e, Callichirus santarosaensis (modified from Sakai and Türkay 2012 ); f, Callichirus seilacheri , MZUCR 3335–01. Scale bars: 10 mm. Figure 9. Male pleopod 2 and third maxilliped, external surface. a, Callichirus adamas (modified from Kensley 1974 ); b, Callichirus corruptus sp. nov. , MZUSP 41251; c, Callichirus islagrande , USNM 69362; d, Callichirus major , USNM 228086; e, Callichirus santarosaensis (modified from Sakai and Türkay 2012 ); f, Callichirus adamas (modified from Kensley 1974 ); g, Callichirus garthi , MZUC-UCCC 7311; h, Callichirus seilacheri , MZUCR 3335–01. Scale bars: a–d = 1 mm; e–h = 5 mm. Figure 10. a, Callichirus aff. major Colombia, male major cheliped dactylus and fixed finger, lateral view, USNM 266225; b, Callichirus corruptus sp. nov. , male major cheliped dactylus and fixed finger, lateral view, MZUSP 41251; c, Callichirus corruptus sp. nov. , female major cheliped merus, lateral view, MZUSP 41252; d, Callichirus garthi , male major cheliped ischium, lateral view, MUAP-CD 0432–2011; e, Callichirus garthi , sixth pleomere, uropods and telson, dorsal view, MUAP-CD 0432–2011; f, Callichirus islagrande , male major cheliped merus and ischium (courtesy of Nuno Simões), lateral view; g, Callichirus adamas , male major cheliped merus and ischium (modified from Kensley 1974 ), lateral view; h, Callichirus islagrande , sixth pleomere, uropods and telson, dorsal view, USNM 69362. Scale bars: 10 mm. Diagnosis Carapace with small triangular rostrum and two rounded anterolateral projections. Ocular peduncles contiguous except for separated blunt apical portion, not reaching second article antennular peduncles. Antennular peduncle longer and stouter than antennal peduncle, second article of antennular peduncle slightly exceeding fourth article of antennal peduncle. Maxilliped 3 merus with distal and proximal margins not parallel, strongly oblique distally, not projecting beyond carpo-meral articulation. Male major cheliped merus with prominent hook on lower margin; fixed finger with small triangular tooth at mid length of cutting edge; dactylus strongly arcuate with tip curved downward, bifid, longer than fixed finger, cutting edge with large bifid tooth proximally, otherwise unarmed. Male pleopod 2 with endopod and exopod well developed. Telson slightly broader than long, tapering distally, emarginate posteriorly. Description Carapace length of adults up to 23 mm . Carapace smooth, cervical groove and linea thalassinica well developed, cardiac prominence absent, lateral margin of carapace emarginate on central part, branchiostegal lobe well-produced anteriorly beyond junction with oblique branchiostegal ridge ( Figure 2a, b ); rostrum short, triangular; anterolateral projections rounded ( Figure 2c ). Branchial formula is presented in Table 3 . Ocular peduncles ( Figure 2c ) contiguous except for separated blunt apical portion, not reaching second article antennular peduncles; cornea subterminal and lateral, small (width less than half width of ocular peduncle), darkly pigmented. Antennular peduncle ( Figure 2b, c ) longer and stouter than antennal peduncle, lower margin with dense rows of long setae; basal article overlain by eyestalk; second article slightly exceeding fourth article of antennal peduncle; terminal article about twice as long as second article. Antennular flagellum with dorsal and ventral ramus similar in length, both with sparse, long tufts of setae, composed of 21–23 articles, respectively. Table 3. Branchial formula for Callichirus corruptus sp. nov.
Maxillipeds Pereopods
1 2 3 1 2 3 4 5
Exopods 1 1 - - - - - -
Epipods 1 1 - - - - - -
Podobranchs - - - - - - - -
Arthrobranchs 1 2 2 2 2 2 -
Pleurobranchs - - - - - - - -
Antennal peduncle ( Figure 2b ) reaching mid length of antennular peduncle third article; basal article short, excretory pore protruded, densely setose; second article with setose laterally; third article shorter than second; fourth and fifth articles subequal in length, fourth article with sparse setae laterally, fifth article with tuft of short setae distolaterally; scaphocerite small, blade-shape ( Figure 2d ). Mouthparts typical for genus according to external observation, not illustrated. Maxilliped 3 ( Figure 2e ) without exopod; ischium-merus operculiform, length about 1.2 times its width, setose marginally; ischium without crista dentata on mesial surface, 1.4 times length of merus; distal and proximal margin of merus not parallel, strongly oblique distally, not projecting beyond carpo-meral articulation; carpus and propodus expanded ventrally; dactylus digitiform, shorter than propodus. Chelipeds (pereopods 1) unequal and dissimilar in males and females ( Figures 1a , 2a , 3a– d ). Male major cheliped ( Figure 3a ) extremely elongated and strongly calcified; ischium ventral margin with row of well-spaced blunt teeth, dorsal margin nearly straight; merus with prominent hook on lower margin, hook margin strongly serrate, remainder of hook lower margin with irregular rounded denticles, hook dorsal margin slightly denticulate and concave; carpus length about 1.5 times as long as palm, about twice longer than wide, dorsal margin straight, unarmed, ventral margin slightly expanded medially, with rounded denticles at proximal third, sparse setae; palm rectangular, longer than width, dorsal and ventral margins smooth, with sparse setae on ventral margin; fixed finger with triangular tooth at mid length of cutting edge; dactylus strongly arcuate with tip curved downward, bifid, longer than fixed finger, cutting edge with large bifid tooth proximally, otherwise unarmed. Male minor cheliped ( Figure 3c ) slender; ischium longer than merus, dorsal and ventral margin smooth; merus narrower than carpus, dorsal margin smooth, slightly convex, ventral margin with spaced tufts of short setae; carpus longest article, lateral sulcus, dorsal margin of carpus slightly curved, ventral margin of carpus slightly expanded, with row of tufts of short setae; palm about half length of carpus, dorsal margin unarmed, ventral margin with row of tufts of short setae, fixed finger approximately as long as dactylus, occlusal margin armed by serration of small acute denticles; dactylus slightly arcuate, occlusal margin armed by serration of small acute denticles, with tuft of setae dorsally. Female major cheliped ( Figure 3b ) less elongate than in males, differing from male larger cheliped as follows: dorsal and ventral margin of ischium straight; merus with less prominent hook on lower margin, margin of hook weakly granulate, dorsal margin hook smooth, curved; carpus as long as palm; cutting edge of fixed finger with two acute teeth at proximal third, as long as dactylus; dactylus slightly curved, occlusal margin with small acute denticles. Female minor cheliped ( Figure 3d ) as in males, differing only in having dorsal and ventral margins of merus convex, cutting edges of fixed finger, dactylus unarmed and setation pattern. Pereopod 2 ( Figure 4a ) chelate, densely setose ventrally; ischium about 1.4 times as long as wide; merus slightly longer than carpus, lower margin sinuous, with row of long setae, dorsal margin slightly convex; carpus subtriangular, widening distally, dorsal and ventral margin with sparse long setae; palm less than 0.5 times as long as carpus, fixed finger subtriangular, cutting edge smooth; dactylus lanceolate, cutting edge smooth, densely setose dorsally. Pereopod 3 ( Figure 4b ) pediform; ischium subsquare, unarmed; merus about two times longer than ischium, ventral and dorsal margins slightly convex and non-setose; carpus subtriangular, widening distally, distal margin with tuft of setae dorsally; propodus expanded proximally, produced into rounded posterior lobe, heavily setose; dactylus broad, with two small notches distally, heavily setose. Pereopod 4 ( Figure 4c ) subchelate; ischium more than half of merus, unarmed, margins non-setose; merus slightly wider than ischium, arcuate ventrally; carpus widening distally, almost equal in length to propodus, margins non-setose; propodus wider than carpus, with lower-distal projection, surface densely covered with short setae; dactylus digitiform, two small notches on the upper border, surface densely covered with short setae. Pereopod 5 ( Figure 4d ) chelate, fingers not gaping; ischium rectangular, unarmed; merus longest, about 2.7 times longer than ischium, unarmed; carpus subtriangular, widening distally, unarmed; inner and outer surface of propodus densely setose in distal half; surface of dactylus covered with dense setae. Pleon ( Figure 2a ) glabrous dorsally, except for subcircular patches of setae adjacent to lateral margins of somites 3 to 5 representing integumental glands; pleon about 5.7 times as long as carapace; length ratio of first to sixth pleomeres and telson measured along midline 3.3:4.3:1.7:1.6:2.0:1.9:1.0, first and second pleomeres combined longer than third to fifth pleomeres combined (1.3:1.0). First and second pleomeres translucent ( Figure 1a ); first pleomere narrowing anteriorly in dorsal view, shorter than second one, connection between the dorsal and ventral sclerites perceptible as a fine suture running obliquely in the anteposterior sense; second pleomere longest, widening posteriorly in dorsal view, tergite rounded posterolateral lobe below suture sclerotised at least as heavily as remainder of tergite. Pleomeres 3–5 ( Figure 1a ) similar in length, third to fifth tergites each laterally encompassing finely pubescent, membranous subcircular area below posterolateral suture, membraneous areas of third and fourth tergite more posteriorly positioned than on fifth, that of fifth tergite slightly smaller, less circular. Sixth pleomere ( Figure 5a ) saddle-like, 1.2 times as wide as long; pleurites globose dorsally, tergite with a transverse groove on each side and a longitudinal groove at posterior half; posterior margin bilobed by short median notch, with 2 pairs of tufts of short setae posteriorly.Telson ( Figure 5a ) slightly broader than long,tapering distally, emarginate posteriorly; lateral margin with small lobe proximally, followed by deep notch and another large lobe at mid length to lateral margin; dorsal surface separated into three lobes, one large anterior and two smaller posterolateral separated by deep central notch. Pleopod 1 ( Figure 5b, c ) uniramous and slender in both sexes, composed of two articles in males, three articles in females. Male first pleopod ( Figure 5b ) with two equally long articles, distal article narrowing distally, sparse setae on the tip. Female first pleopod ( Figure 5c ) longer than male one, basal article L-shaped, second article about twice as long as terminal article, terminal article forming narrow flattened blade, terminal article margin fringed by short setae. Pleopod 2 ( Figure 5d, e ) biramous in both sexes; in males and females endopod and exopod well developed, exopod slightly shorter than endopod; second pleopod of male non-setose, male endopod without appendices interna and masculina; in females endopod with well-developed and terminal appendix interna, surface of appendix interna covered with patch of short hooked setae. Pleopods 3 to 5 ( Figure 5f ) biramous, leaf-like, endopod broadened, with subtriangular appendix interna embedded into mesial margin of endopod in both sexes. Uropod ( Figure 5a ) with protopod dorsally divided into four irregular lobes, posterolateral lobe ending in spinous process projected distally; endopod strap-shaped, much longer than wide, exceeding posterior margin of telson, base with rounded lobe ending in a spine protruded distally; exopod triangular with anterodorsal plate shorter than posterodorsal plate, both with distal margin densely setose. Colour In life ( Figure 1a ) most individuals appear white to hyaline on all sclerotised parts, including chelipeds, sixth pleomere, telson and uropods. The branchiostegites and part of the dorsal oval of the carapace are poorly sclerotised, whereas most of the pleon is translucent in dorsal view. In males, the liver gland is visible in deep yellow through the cuticle of the first and second abdominal somites in dorsal view. Interestingly, the male gonad has an ovarian section that runs between the posterior region of the second pleomere and the anterior region of the fourth pleomere, which is dorsally visible due to its orange colouration. In females, this gland is partially covered by the ovaries, which in mature females are reddish orange. Pattern of dorsal abdominal grooves more whitish in adult males and females.
Distribution Known from Praia do Crispim , Pará to Balneário Camboriú, Santa Catarina , Brazil ( Figure 1b ) . Habitat Callichirus corruptus sp. nov. forms simple burrows with one opening, normally inhabited by only one individual, in the intertidal zone of fine-grained sandy beaches. This ghost shrimp is often the only axiidean species present in the intertidal zone of many beaches. The pinnotherid crabs Austinixa aidae ( Righi, 1967 ) and A. patagoniensis ( Rathbun, 1918 ) are normally found living within the galleries of C. corruptus sp. nov. (Hernáez 2018). Etymology From the Latin, corruptus referring to the name that local harvesters give to the species of Callichirus along the Brazilian coast.