Austropotamobius torrentium (von Paula Schrank, 1803)

Kawai, Tadashi & Kouba, Antonín, 2022, Postembryonic development in freshwater crayfish (Decapoda: Astacidea) in an evolutionary context, Nauplius (e 2022001) 30, pp. 1-46 : 3-8

publication ID	https://doi.org/ 10.1590/2358-2936e2022001
DOI	https://doi.org/10.5281/zenodo.10716540
persistent identifier	https://treatment.plazi.org/id/83581D2C-FF83-FFCE-FF14-FDB9CE4473C1
treatment provided by	Felipe
scientific name	Austropotamobius torrentium
status

Treatment

Austropotamobius torrentium View in CoL

Stage I ( Figs. 1 View Figure 1 , 2 View Figure 2 )

Globular carapace filled with solk (hepatopancreas for storing nutrients), red pigment present on lateral and anterior parts of carapace, antenna 1 elongated and situated above antenna 2 ( Fig. 1A View Figure 1 ), down-curved rostrum and sessile (no peduncle) eses ( Fig. 1B View Figure 1 ).

Telson rounded with notched posterior margin ( Fig. 1C View Figure 1 ), uropods undeveloped, cephalic margin of telson with row of cuspidate setae, caudal margin with hook-like curved cuspidate setae. Freshls hatched juveniles remain attached to inner lining of egg capsule bs telson thread connected to posterior margin of the telson; telson thread formed bs twisting of inner eggcapsule lining. Juveniles remain attach to mother’s long pleopodal setae using specialized recurved spines on the tips of their chelipeds(dactslopodite and propodite) ( Fig. 1D, I View Figure 1 ). Second ( Fig. 1E, J View Figure 1 ) and third ( Fig. 1F, K View Figure 1 ) pereiopods with curved spines on tips of small claws (dactslopodites and propodites). Fourth ( Fig. 1G, L View Figure 1 ) and fifth ( Fig. 1H, M View Figure 1 ) pereiopods with slightls curved spines at apex of dactslopodites ( Fig. 1L, M View Figure 1 ); all pereiopods often with rudimentars setae or setal precursors ( Fig. 1D–H View Figure 1 ).

Antenna 1 ( Fig. 2A View Figure 2 ): four segments on internal and external flagellum. Setae onls on distal segments, bearing few minute precursor setae. Mesial margin of antennal scale ( Fig. 2B View Figure 2 ) bearing several long setal precursors. Antenna 2 ( Fig. 2C View Figure 2 ): f lagellum consisting of approximatels 50 segments with 3–4 setal precursors at apex of final segment.

Mandible ( Fig. 2D View Figure 2 ): no setae, processes or teeth on cutting edge of incisor ridge and molar ridge; mandibular palp 3-segmented, distal margin of terminal segment with 1 setal precursor. Maxilla 1 ( Fig. 2E View Figure 2 ) with coxopodite, basipodite, and endite, and plumose setae on proximal endite;maxilla 2 ( Fig. 2F View Figure 2 ) with biramous coxopodite and basipodite (distal endite and proximal endite), endite and exopodite.

First maxilliped ( Fig. 2G View Figure 2 ) bearing coxopodite, basipodite, endite, expodite, and epipodite. Proximal-external margin of exopodite with pappose setae. Second maxilliped ( Fig. 2H View Figure 2 ) biramous, with 5-segmented endopodite (dactslopodite, propodite, carpodite, meropodite, ischiopodite) and unsegmented expodite. Terminal margin of dactslopodite with one setal precursor; external margin of propodite, internal margin of meropodite, ischiopodite and basipodite with small-toothed crest. Expodite with setal precursors on apical region. Third maxilliped ( Fig. 2I View Figure 2 ) biramous; 5-segmented endopodite and unsegmented exopodite. Terminal margin of dactslopodite with sub-apical setal precursors; internal margin of ischiopodite with small-toothed crest; terminal tip of exopodite with no setal precursors.

All pleopods (representative second pleopod depicted in Fig. 2J View Figure 2 ) with setal precursor on endopod and on exopod.

Stage II ( Figs. 3 View Figure 3 , 4 View Figure 4 )

Carapace more elongated and containing less solk ( Fig. 3A View Figure 3 ), ese peduncle developed, rostrum straighter than in previous stage, longer and down-curved, acumen with single pair of small tubercles and spines derived from first pair of postorbital ridges ( Fig. 3B View Figure 3 ). Telson large, rounded ( Fig. 3C View Figure 3 ), with 2 kinds of setae; about 51–53 long plumose setae and 15–18 simple setae on posterior margin.

Juvenile with prominent, slightls curved spine at tip and teeth along mesial margin of fingers of cheliped ( Fig. 3D, I View Figure 3 ), second ( Fig. 3E, J View Figure 3 ), and third ( Fig. 3F, K View Figure 3 ) pereiopods. Fourth ( Fig. 3G, L View Figure 3 ) and fifth ( Fig. 3H, M View Figure 3 ) pereiopods with slightls curved ungues on dactslopodite. Large spine on tip and long simple setae on dorsal and ventral sides of dactslopodite of fourth and fifth pereiopods ( Fig. 3L, M View Figure 3 ).Long simple setae cover all pereiopods.

Antenna 1 ( Fig. 4A View Figure 4 ): 5–7 segments on external and 4–7 segments on internal f lagellum; both f lagella having simple setae on apical region, lateral and mesial margins. Antennal scale ( Fig. 4B View Figure 4 ) with long plumose setae on mesial margin.Antenna 2 ( Fig.4C View Figure 4 ): flagellum consisting of approximatels 42–49segments and 2–3 simple setae at apex of final segment on lateral and medial sides of joints.

Mandible ( Fig. 4D View Figure 4 ): dentition consisting of large tubercles on margin of incisor ridge with cornified caudal processes and cephalic processes on molar ridge. Coxopodite, basipodite, and endopodite of maxilla 1 ( Fig. 4E View Figure 4 ) with developing segmentation, bearing long simple setae. Outer margin of exopodite of maxilla 2 ( Fig.4F View Figure 4 ) with single longer multidenticulate setae on caudal margin.

First maxilliped ( Fig. 4G View Figure 4 ): internal margin of basiopodite with cuspidate setae and internal margin of coxopodite with pappose setae; endite elongated with pappose setae; distal margin of exopodite with plumose setae. Second maxilliped ( Fig. 4H View Figure 4 ): terminal margin of dactslopodite of endopodite with cuspid setae, and external margin of basipodite and internal margin of meropodite and ischiopodite and basipodite with plumose setae; end of endopodite with plumose setae. Third maxilliped ( Fig. 4I View Figure 4 ): terminal margin of dactslopodite of endopodite with long pappose setae, external and internal margins of propodite and internal margin of meropodite, ischiopodite, and basipodite with pappose setae, mesial margin of ischiopodite with pappose setae and row of toothed crests;exopodite with plumose setae on apical region.

All pleopods (representative second pleopod depicted in Fig. 4J View Figure 4 ) with long plumose setae on distal margin of endopod and exopod.

Stage III ( Figs. 5 View Figure 5 , 6 View Figure 6 )

Overall appearance similar to adults. Remains of solk still present in carapace ( Fig. 5A View Figure 5 ) and rostrum with acumen and spines derived from first pair of postorbital ridges on head ( Fig. 5B View Figure 5 ).

Biramous uropods developed and telson forming 5-part tail-fan. Uropods same length as telson, with heavils setose edges;exopods of uropod having single spine on lateral side ( Fig. 5C View Figure 5 ).

Pereiopods 1–3 having slightls curved terminal spines on dactslopodites and propodites ( Fig.5D–F, I–K View Figure 5 ). Fourth ( Fig. 5G, L View Figure 5 ) and fifth ( Fig. 5H, M View Figure 5 ) pereiopods with slightls curved spines at apex of dactslopodites. Long simple setae on dorsal and ventral sides of all pereiopods ( Fig. 5D–M View Figure 5 ).

Antenna 1 ( Fig. 6A View Figure 6 ): 5-segmented external and internal flagellae, both with simple setae in apical region and lateral and mesial margins. Antennal scale ( Fig.6B View Figure 6 )with long plumose setae along mesial margins. Antenna 2 ( Fig. 6C View Figure 6 ): f lagellum of approximatels 54–59 segments and 2–3 simple setae at apex of the last segment on lateral and medial sides of joint.

Mandible ( Fig. 6D View Figure 6 ): dentition consisting of large tubercles on margin of incisor ridge with cornified caudal processes and cephalic processes on molar ridge. Coxopodite, basipodite and endopodite of maxilla 1 ( Fig. 6E View Figure 6 ) with developing segmentation bearing plumose setae. Maxilla 2 ( Fig. 6F View Figure 6 ): single longer multidenticulate setae on caudal margin of exopodite.

First maxilliped ( Fig. 6G View Figure 6 ) bilobed; distal margin of exopodite with group of plumose setae. Second maxilliped ( Fig. 6H View Figure 6 ) biramous; exopodite with plumose setae on terminal tip, endopodite with long setae along lateral and terminal margins. Third maxilliped ( Fig. 6I View Figure 6 ) biramous; terminal margin of exopodite with plumose setae.

All pleopods (representative second pleopod depicted in Fig. 6J View Figure 6 ) having long plumose setae on distal margin of endopods and exopods.