Aegla nebeccana, Trombetta & Páez & Santos & Teixeira, 2019

Trombetta, Alana De Souza, Páez, Fernanda Polli, Santos, Sandro & Teixeira, Gustavo Monteiro, 2019, Aegla nebeccana n. sp. (Crustacea, Aeglidae) from Ivaí Basin, Paraná, Brazil, Zootaxa 4712 (1), pp. 138-150 : 140-145

publication ID	https://doi.org/ 10.11646/zootaxa.4712.1.10
publication LSID	lsid:zoobank.org:pub:22737A82-51B6-49F7-9BB1-726FACA4571D
persistent identifier	https://treatment.plazi.org/id/03E88452-FFDE-FFCB-FF13-FB6EFB95F86F
treatment provided by	Plazi
scientific name	Aegla nebeccana
status	sp. nov.

Treatment

Aegla nebeccana View in CoL n. sp.

( Figs 2–8 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 )

Type-Material. Holotype: MZUEL 222 , male ( CLE 17.6 mm), Brazil, Paraná, Borrazópolis, Paraná River basin, Ivaí River sub-basin, 24°01’32.85”S, 51°36’46.98”W, 375 m, coll. G. Teixeira. GoogleMaps

Paratypes (all the same locality and collector as the holotype) : MZUEL216 , 1 male ( CLE 20.2 mm), April 2016 . MZUEL218 , 1 male ( CLE 15.4 mm), August 2015 . MZUEL219 , 1 male ( CLE 10.2 mm), June 2016 . MZUEL222 , 1 male ( CLE 17.6 mm), 1 female ( CLE 9 mm), August 2016 . MZUEL223 , 2 males ( CLE 10.5–16.1 mm), April 2016 . MZUEL224 , 3 males ( CLE 16.0– 14.5 mm), 3 females ( CLE 13.0– 14.1 mm), January 2015 . MZUEL225 , 1 male ( CLE 12.4 mm), April 2014 . MZUEL214 , 1 female ( CLE 12.5 mm), September 2015 . MZUEL 220 mm, 1 female ( CLE 14.8 mm), May 2015 . MZUEL226 , 6 females ( CLE 12.7–15.5 mm), August 2016 . MZUEL227 , 6 females ( CLE 10.6 –17.0 mm), July 2016 .

Non-Type Material. Genetic voucher: Bold Systems access AEGIV001-19 , AEGIV002-19 (same locality and collector as the holotype, specimens are deposited in the crustacean collection of the Federal University of Santa Maria , Rio Grande do Sul, Brazil, catalogue number 480) .

Geographical distribution. This species is presently known only from Lageadão River, State of Paraná, Paraná River hydrographic basin, Ivaí River sub-basin.

Diagnosis. Carapace slightly protuberant. Triangular rostrum with narrow base, slightly curved downwards. Prominent rostral carina beginning at height of protogastric lobes extending to the apex of the rostrum. Protogastric lobes developed and protruding. Orbital sinus slightly shallow, externally limited by orbital tubercle. Shallow extra-orbital sinus. First hepatic lobe delimited by deep groove, followed by 2° evident and 3° hepatic lobe sparsely delimited with modest indicative of demarcation. Anterior angle of ventral margin of epimeron 2 unarmed. High palm, palmar crests of major cheliped rectangular. Palmar crest of minor cheliped rectangular or subdisciform. Carpal crest of carpus weakly marked in distal region. Merus of cheliped with ventromesial border ornate with distal spine followed by tubercles. Ventromesial face of ischium of cheliped ornate, with proximal and distal prominent tubercle and up to 2 rudimentary tubercles between them. Narrow uropod.

Minor cheliped (right) similar to major cheliped ( Figs 7A, B View FIGURE 7 ) except as noted. Dactylus ( Fig. 7B View FIGURE 7 ) occlusal margin with less developed proximal lobular teeth followed by smaller denticles and tufts setae in greater concentration on the distal region. Propodus with rectangular to subdisciform palmar crest ( Fig. 7B View FIGURE 7 ).

Description of male holotype. Carapace moderately protruding; gastric region protruding; irregular dorsal region with punctuations (CC = 20.7 mm; CLE = 17.6 mm) ( Figs 3A View FIGURE 3 , 5A, D View FIGURE 5 ). Front LPC/LF = 1.53. Rostrum triangular, narrow base (RBW/LMR = 0.97), curved slightly downwards, extending beyond apex of compound eyes (total rostrum length = 3.7 mm) ( Fig. 5A View FIGURE 5 ). High rostral carina, beginning at level of protogastric lobes ( Figs 5A, C View FIGURE 5 ), extending to near apex, with two 2 parallel rows of scales, changing to 1 row on distal portion near apex; sub-rostral process developed.

Wide and shallow orbital sinus (LO/LSEO = 3.4), externally limited by rudimentary orbital tubercle. Anterolateral angle of carapace anteriorly projected, with conical spine, anteriorly salient reaching base of cornea. Outer margin of anterolateral lobe ornamented with rudimentary scales ( Fig. 5C View FIGURE 5 ).

Epigastric prominences inconspicuous, demarcated by few scales ( Figs 5A, B View FIGURE 5 ). Protogastric lobes developed and protruding, ornamented by few scales ( Figs 3A View FIGURE 3 , 5A, B View FIGURE 5 ). First hepatic lobe delimited anteriorly by distinct groove; 2 nd hepatic lobe distinct; 3 rd hepatic lobe modestly marked.

Transverse dorsal line slightly sinuous throughout its extension, more pronounced sinuosity on mid-region. Sub-rectangular areola ({h/[(x+y)/2]} = 2.15). Cardiac area trapezoidal (TDL/DDL= 1.36) ( Fig. 5E View FIGURE 5 ).

Epibranchial sub-rectangular area, with scales on margins. Lateral margin of anterior branchial area with scarce scale and setae, posterior area with scarce setae.

Anterior angle of ventral margin of epimeron 2 unarmed ( Fig. 3E View FIGURE 3 , 5F View FIGURE 5 ), with small scales and setae. Ventrolateral margin slightly concave. Posterior angle of ventral margin apically rounded, unarmed, ornamented with setae.

Telson divided by longitudinal suture. Narrow uropod (MWE/MW= 0.93) ( Fig. 3B View FIGURE 3 , 6A View FIGURE 6 ).

Anterior extremity of 3 rd sternite tapered, with tufts of long setae ( Fig. 3D View FIGURE 3 , 6B View FIGURE 6 ). Fourth thoracic sternite with ornamented margin with tufts of long setae, median region slightly flattened, with small prominence between tufts of setae and small tufts of short setae at posteromedially.

Major cheliped (left). Dactylus ( Fig. 7A View FIGURE 7 ): granulated and ornamented dorsal and outer margins, with short scales; pre-dactylar lobe moderately developed; occlusal margins of fingers with lobular denticles in median and proximal region; squamiform denticles at distal region, with setae ornament; dorsal margin of dactylus without lobe. Propodus ( Fig. 7A View FIGURE 7 ): granulated outer surface with globous aspect; smooth ventral margin; high palm (a+b/c = 3.65); rectangular palmar crest, with smooth margin or lightly toothed if compared to smaller cheliped. Carpus subcylindrical ( Fig. 7C View FIGURE 7 ), ornamented dorsal margin with distal tubercle, 2 proximal tubercles and up to 2 robust tubercles between them; anterolateral angle of inner surface with scales and tubercle on apex. Merus: dorsolateral margin with more prominent distal tubercle, followed by tubercles and scales; ventromesial margin with distal spine followed by tubercles and ventrolateral margin with distal tubercle followed by scales. Ischium ( Fig. 7E View FIGURE 7 ): dorsolateral margin with spine or evident tubercle; ventromesial margin ornamented with distal tubercle, proximal tubercle and up to 2 rudimentary tubercles between them.

Pereopods 2–4 with outer and ventral margins of dactylus, propodus and carpus with longitudinal lines of short setae and scales; outer margin of merus with long setae, ventral margin with small distal tubercles; ventromesial face of ischium of 2 nd pereiopod with tubercles and tufts of long setae.

Variations. The anterolateral angle of the carapace, with a conical spine protruding anteriorly, may not reach the base of the cornea ( Figs 8A, B View FIGURE 8 ). In 24 of the 29 specimens analyzed in the paratypic series, the conical spine reaches the base of the cornea.

The shape of the areola from trapezoidal (n = 3) to sub-rectangular (n = 26). The cardiac area may also vary from trapezoidal (n = 7) to sub-rectangular (n = 22).

The fourth thoracic sternite may vary from conical to truncate, and the small tufts of short setae on the midposterior region may be absent or smaller, changing according to the ontogeny of the animal ( Figs 8C, D View FIGURE 8 ).

The uropod varies between narrow (n = 22) and wide (n = 7).

The propodus of the chelipeds may have a palmar crest with an indented or smooth dorsal margin ( Figs 8E, F View FIGURE 8 ).

The spines and tubercles on the dorsal margin of the carpus may vary in form and in number between 4 and 8. The ventromesial aspect of the ischium can be ornamented with one or two proximal tubercles, a distal tubercle and up to two rudimentary tubercles between them ( Figs 8G, H View FIGURE 8 ).

All measurements are summarized in Table 1 View TABLE 1 and their relationships between the different body dimensions are summarized in Table 2 View TABLE 2

Biology. Unknown.

Etymology. Named in reference to the NEBECC (Crustacean Biology, Ecology and Culture Study Group) in honor of its coordinators Dr. Adilson Fransozo and Dr. Maria Lucia Negreiros Fransozo.