Kingsleya parnaiba, Pinheiro William Santana, 2020

Kingsleya parnaiba View in CoL n. sp.

( Figs. 2A–E View Figure 2 ; 3A, B, D View Figure 3 ; 4A–D View Figure 4 )

Zoobank: urn:lsid:zoobank.org:act:C0E6458B-EEB0-4E29-88BD-BD954BBB487B

Type material. Male holotype, cw 49.7mm, cl 32.4mm, Brazil, Piauí State, Ribeiro Gonçalves, Riacho do Manezinho , 07°33’20”S 45°14’31”W, 19.v.2019, G.P.B. Silva coll., in covo traps ( MZUSP 40264 View Materials ) GoogleMaps . — Paratypes collected at the same locality: 1 male, cw 34.4mm, cl 22.3mm; 1 female, cw 56.9mm, cl 36.4mm ( MZUSP 40265 View Materials ) GoogleMaps ; 3 females, cw 42.2mm, cl 29.7mm; cw 45.7mm, cl 30.6mm; 52.5mm, cl 35mm ( MZUSP 40266 View Materials ) .

Comparative material. Kingsleya attenboroughi : Brazil, Ceará, Barbalha, Arajara district , 07°20’07.6”S 39°23’58.8”W, 17.iv.2016, male holotype, cw 46mm, cl 29.2mm, ( MZUSP 34626 View Materials ) GoogleMaps . Paratypes: Brazil, Ceará, Barbalha, Arajara district, Córrego do Arajara , 04.v.2016, 1 male, cw 51.2mm, cl 31mm ( MZUSP 34627 View Materials ) ; 1 female, cw 41.5mm, cl 26.7mm ( MZUSP 34628 View Materials ) ; 1 male, cw 40mm, cl 26.1mm, 1 female, cw 35mm, cl 23mm ( INPA 2208 View Materials ) ; 2 males, cw 36.8mm, cl 24mm; cw 36mm, cl 24mm; 1 female, cw 37.7mm, cl 24mm (LACRUSE 0221). — K. castrensis : Brazil, Pará, Caverna Pedra da Cachoeira , 03°19’14.8”S 52°19’53.1”W, R. Pinto-da-Rocha coll., 20.vi.2012, male, paratype, cw 50.9mm, cl 30mm ( MZUSP 26394 View Materials ) GoogleMaps ; Pará, Altamira , 03°19’14.8”S 52°19’53.1”W, R. Pinto-da-Rocha coll., 24.iii.2012, male, paratype, cw 32.7mm ( MZUSP 25943 View Materials ) GoogleMaps . — K. gustavoi : Brazil, Pará, Rio Itacaiúnas , Projeto Carajás, 17.vii.1988, 2 male paratypes, cw 37mm, cl 23.3mm; cw 19.5mm, cl 12.2mm ( MZUSP 9699 View Materials ) ; Pará, Canaã dos Carajás , Gruta NV06, Andrade and Amoni coll., 22–28.v.2005, C. Magalhães det., 2 males ( MZUSP 16702 View Materials ) . — K. junki : Brazil, Pará, Rio Xingú, Vitória do Xingú , 02°53’S 52°01’W, R. Santos, C. Maciel and J.O. Dias coll., 03.xii.2000, male holotype, cw 33mm, cl 20.8mm ( MPEG 777 View Materials ) GoogleMaps . — K. latifrons : Suriname, Anapaika Village, Rio Lawa , B. Malkin coll., 26.xi.1963, C. Magalhães det., 2 males, 2 females ( MZUSP 1887 View Materials ) ; French Guiana, Cayenne , M. Mélinon coll., sampling date unknown, M. Campos det. in vi.1997, 1 male ( USNM 30028 About USNM ) ; Brazil, Pará, Rio Trombetas, Cachoeira Porteira , V. P. Daniel et al. coll., 10.iv.1985, C. Magalhães det., 1 male, 1 female ( MZUSP 7008 View Materials ) ; Amazonas, Imbó, Rio Uatumã , Cachoeira Morena , E. Ferreira et al. coll., 07.x.1987, 4 males ( MZUSP 11673 View Materials ) . — K. ytupora : Brazil, Pará, Rio Trombetas , Cachoeira Porteira, C. Magalhães et al. coll., 2–10.x.1985, 1 male, paratype, cw 48mm, cl 28.5mm, 2 females, paratypes, cw 64.5mm, cl 38mm; cw 55.6mm, cl 33mm ( MZUSP 7009 View Materials ) .

Description. Carapace ellipsoidal, 1.5 times wider than long, widest medially, dorsally smooth, slightly convex anteriorly, regions poorly defined. Two distinct gastric pits on metagastric region. Cervical grooves marked, narrow, slightly divergent anteriorly, fading proximally, distal end almost reaching anterolateral margin. Intestinal, cardiac regions indistinct. Postfrontal lobules inconspicuous; median groove indistinct. Carapace between front, postfrontal lobules smooth, weakly concave. Front upper border smooth, angulate, slightly bilobed in dorsal view, median notch faint; lower border carinated, slightly sinuous in frontal view, not visible in dorsal view. Superior orbital margin smooth, lower orbital margin crenulated; exorbital angle low, somewhat acute; orbital cavity with several thick setae near exorbital angle. Inner orbital tooth well developed, broadly triangular, partially occluding orbital cavity. Anterolateral margin of carapace with very distinct depression just behind exorbital angle, followed by a set of minute teeth increasing in size from the anterior to posterior portion; posterolateral margin smooth, poorly defined.

Epistome narrow, deeply grooved transversally, upper margin straight, lower margin forming a mesial triangular tooth, deflexed, crenulated. Subhepatic region smooth; pterystogomial region with scarce pubescence bordering buccal frame.

Endopod of maxilliped 3 with ischium outer margin almost straight, subrectangular, slightly wider than merus; mesial margin setose, crista dentata with small, subquadrate, corneous teeth. Merus shorter than ischium, as wide as long, inner margin almost straight, with a small proximal lobe covered with several long setae; outer margin curved distally. Inner surface of palp covered with very few, small setae; outer margin of propodus and dactylus densely covered with long setae, carpus with few long setae. Third maxilliped exopod vestigial, about one fifth of ischium lateral margin length. Aperture of efferent branchial channel wide, subquadrate, lacking setae.

Chelipeds heterochelous in both males, females, more pronounced in males, similarly armed, right P1 usually largest (holotype left cheliped largest). Merus subtriangular in cross section; upper, mesial margins distinctly crenulated; inferior lateral margin with row of distinct small tubercles, not reaching the proximal, distal margins; distal margin arched, smooth laterally, crenulated mesially. Carpus with inner margin indented proximally, with prominent median spine, smooth distally; outer margin rounded, smooth. Propodus massive, upper, mesial, lateral, ventral surfaces smooth. Movable, fixed fingers with lateral, mesial, dorsal surfaces with punctations arranged in longitudinal subparallel lines; movable finger distinctly curved downwards. Largest cheliped with fingers noticeable gaping, tips crossing distally; cutting edges of fingers with small, acute teeth; fixed finger with two teeth medially slightly larger than others; movable finger with few stronger teeth intercalated with smaller teeth. Smaller cheliped with gap between fingers less pronounced than larger one, with movable finger slightly arched; teeth shorter, more similar in size than larger cheliped. Smaller males and female chelipeds with smaller gaps between fingers, less curved movable fingers. P2–P5 slender, similar in shape, decreasing in size very slightly from P2 to P5. P2–P5 meri upper margin with sparse row of minute spines; dactyli punctuate in all surfaces, with five longitudinal rows of sharp spines, 3 dorsal, 2 ventral, increasing in size distally.

Thoracic sternum longer than broad. Sternites 1 to 4 fused. Sternal sutures 4/5 to 7/8 very distinct, sternal sutures 4/5 and 5/6 ending just before reaching median line of thoracic sternum, sternal sutures 6/7 and 7/8 ending in median line of thoracic sternum. Episternites 4–6 subtriangular, episternite 7 shorter, truncated in males, triangular in females. Episternites 4–7 fringed with short setae, longer in females.Sternoabdominal cavity deeply excavated, shallower in females; sternites 5 to 8 densely covered medially with distinct long, thin setae, sternite 4 with few long setae in males, females with sparse setae mostly on sternites 1–4; tubercle of abdominal holding system reduced in males, almost imperceptible in females, placed near sternal suture 5/ 6 in males. Male and female pleon with 6 free somites. Male pleon tapering distally from third to sixth somite; telson triangular; margins, including telson, densely setose, setae short. Female pleon somewhat rounded, sixth somite longer, wider; sixth somite and telson forming a subtrapezoid pleotelson. Penis distinctly long, larger proximally, tapering distally, emerging near coxosternal condyle articulation.

G1 sinuous, broadened distally, abdominal surface with distinct curvature mesially, with well-developed mesial process. Marginal suture in mesial surface, almost straight, displaced to mesial side distally, with several long setae proximally. Lateral suture deep, approximately 2/3 of gonopod length from proximal portion. Marginal process short, broad, subtrapezoidal in mesial view, not projecting distally beyond field of apical spines, distal notch in latero-abdominal surface. Mesial process short, subtriangular, medial portion forming obtuse angle, distal portion protruded into sharp conical spine curved in anteromesial direction, mesial process and apical plate attached. Apical plate with two large, subtriangular lobes, completely separated from each other by distinct groove in mesial and sternal views, proximal lobe with semicircular protuberance compressed in mesial and sternal views; distal lobe with a median constriction, noticeable in lateral and mesial views. Sperm channel opening near the base of apical plate in sternal view. Apical spine field well developed, better visible in sternal view, curved proximally, with a patch of minute spines concentrated medially, longitudinally directed along abdominal side of apical plate, delimited by mesial border of distal lobe and lateral border of proximal lobe of apical plate, distally closed.

G2 slightly sinuous, almost as long as G1, distinctly slender, distal 3/4 tapered; tip f lattened, with numerous short spinules on sternal surface.

Type locality and distribution. So far known only from the type locality in the Riacho do Manezinho, in the municipality of Ribeiro Gonçalves, state of Piauí, Brazil, 07°33’20”S 45°14’31”W. However, due to the proximity of the sampling location to the main channel of the Parnaíba River , we did not rule out the possibility of finding K. parnaiba n. sp. in this river.

Ecological notes. We collected the specimens at the Riacho do Manezinho, a small stream in the peri-urban region of the Ribeiro Gonçalves, an area of recent agricultural expansion, especially with soybean cultivation ( Buainain and Garcia, 2015). The Riacho do Manezinho stream has its margins partially deforested ( Fig.5A View Figure 5 ) and is surrounded by plantations and livestock on the left bank and by an urban area on the right bank. It is located in a flat area of semideciduous tropical Cerrado, locally known as Mata dos Cocais ( Castro et al., 1998), an ecotonal area between Cerrado (a savanna-like biome) and the Amazon forest domains. The stream is located approximately 190 m above sea level; it is shallower than 1 m and 5 to 7 m wide ( Fig. 5B View Figure 5 ). The stream is perennial, with low to medium energy, sandy/muddy bottoms, and turbid waters. Burrows were not observed on the margins or in the riverbed.

Etymology. The specific epithet “parnaíba ” refers to the name of the river basin where the new species was found. The name is used as a noun in apposition.

Remarks. Kingsleya parnaiba n. sp. shares several characters of the G1 with other Kingsleya species: the apical plate of the G1 is bilobed with lobes partially overlapping; the marginal process is distally enlarged, not surpassing the apical field of spines; the mesial process is distinctly separated from the apical plate and stands out from the sternal surface of the principal axis of the G1; and the field of apical spines is distally divided by a terminal notch ( Fig. 4A–D View Figure 4 ) ( Magalhães and Türkay, 2008; Pedraza and Tavares, 2015; Pinheiro and Santana, 2016). Among its congeners, K. parnaiba n. sp. is very similar to K. attenboroughi and to some extent K. gustavoi , but can be distinguished from both by several features. These are: (i) an abdominal surface with distinct curvature mesially (vs. shallow curvature on the abdominal surface mesially in K. attenboroughi and K. gustavoi ; Fig. 4A, E View Figure 4 ); (ii) a medial portion of the mesial process forming an obtuse angle (vs. a mesial process with a straight proximal portion in K. attenboroughi , rounded in K. gustavoi ; Fig. 4B–C, F–G View Figure 4 ); (iii)mesial process and apical plate fused at base (vs. a mesial process separated by a deep notch from the apical plate in K. attenboroughi and a small incision in K. gustavoi ; Fig. 4B–C, F–G View Figure 4 ); (iv) lobes of the apical plate that are completely separated from each other by a distinct groove (vs. lobes of the apical plate that are separated by a groove distally and fused near the base in K. attenboroughi and in K. gustavoi ; Fig. 4C, G View Figure 4 );(v) proximal lobe of the apical plate with a semicircular basal protuberance compressed (vs. a proximal lobe with a conspicuous semicircular basal protuberance in K. attenboroughi and a proximal lobe of the apical plate partially folded distally over the mesial crest of the field of apical spines in K. gustavoi ; Fig. 4A, D, E, H View Figure 4 ). Other morphological differences between K. parnaiba n. sp. and K. attenboroughi are: (vi) female sixth somite and telson forming a subtrapezoid pleotelson (vs. lateral margins of the female sixth somite rounded, with a broadly triangular telson in K. attenboroughi ; Fig. 3B–C View Figure 3 ); and (vii) movable finger of the smaller cheliped slightly arched and about the same size as the palm (vs. movable finger of the smaller cheliped almost straight and slightly shorter than palm in K. attenboroughi ; Fig. 3D, E View Figure 3 ). The characters (vi) and (vii) are observable in all specimens of K. parnaiba n. sp.

A lso, both species, K. parnaiba n. sp. and K. attenboroughi , inhabit different habitats and hydrographic basins. Kingsleya parnaiba n. sp. is found in the lowland areas of the Parnaíba River valley, approximately 190 m above sea level, whereas K. attenboroughi is only found in very small, isolated streams of the Chapada do Araripe, about 750 m above sea level. Kingsleya parnaiba n. sp. inhabits a stream with sandy/muddy bottoms and turbid waters and K. attenboroughi inhabits streams with bottoms of consolidated sandstone blocks and clear water. On the other hand, K. parnaiba n. sp. and K. attenboroughi share the fact that they occur in areas heavily impacted by anthropogenic changes to the environment, with agricultural expansion, deforestation, pollution and irregular use of water resources being the main problems.