The discovery of Euryrhynchidae (Crustacea: Decapoda) in India, with the description of a new genus and species
Author
Grave, Sammy De
Author
Arjun, Charambilly Purushothaman
Author
Raghavan, Rajeev
text
Zootaxa
2018
2018-08-28
4462
3
367
378
journal article
29393
10.11646/zootaxa.4462.3.4
896825be-23b0-42c1-9c31-64d4f027b0b4
1175-5326
1441701
D9517A3B-9B8B-44A0-AAB7-9670A992D242
Eurindicus bhugarbha
sp. nov.
(
FigS. 2–6
)
Type
material.
India
.
Holotype
: male (pocl
3.2 mm
), homeStead well uSed for drinking water and irrigation at Puthiyatheru, Chirakkal
,
Kannur
DiStrict,
Kerala
,
11.911°N
75.364°E
,
29m
a.S.l
,
8.64 m
deep, leg. C.P. Arjun,
07.II.2017
, BNHS CAR 1. ParatypeS: male (pocl 3.0 mm), Same detailS, diSSected, BNHS CAR 2; male (pocl
2.4 mm
), Same detailS, BNHS CAR 3.
Description.
Carapace Smooth, branchioStegal grooVe well-deVeloped (
Fig. 2A–C
); roStrum triangular in dorSal View (
Fig. 2C
), depreSSed, falling Short of diStal margin of eyeS; SparSely SetoSe; Sub-orbital angle poorly deVeloped; antennal tooth marginal, diStinct, confluent with Sub-orbital angle; pterygoStomial angle rounded. EyeS Short (
FigS. 2A–B
), conical, cornea abSent, diStal part of eyeS hyaline, proximal part appearing denSer with diSperSed globuleS; anteromeSial peduncle not produced, without Setae.
Fourth thoracic Sternite (maleS) without tranSVerSal ridge or tooth; fifth thoracic Sternite (
Fig.
2I
) with welldeVeloped tranSVerSal ridge, with broad median lobeS.
Abdomen Smooth (
Fig. 2D
), pleura 1–3 Ventrally rounded; pleuron 2 expanded, oVerlapping both pleuron 1 and 3; pleura 4–5 poStero-lateral angle quadrate; poStero-lateral margin of pleuron 6 produced into rounded lobe.
Antennular peduncle (
FigS. 2E–G
) with Stylocerite expanded into tooth; antero-lateral margin of baSal Segment produced into Sharp, recurVed tooth, reaching middle of Second Segment; Second Segment with both antero-lateral and antero-medial angle bluntly produced, aSymmetrical; third Segment quadrate; lower antennular flagellum long, about 2.5 x carapace length; upper antennular flagellum biramouS, joint portion conSiSting of three diViSionS; acceSSory ramuS Short, with four conical diViSionS; two pairS of aeSthetaScS preSent diStally on third diViSion, fiVe pairS medially and diStally on fourth diViSion.
Scaphocerite broad (
Fig. 2H
), Slightly longer than antennular peduncle; fringed with annular, plumoSe Setae; lateral margin Straight, ending in diStal tooth, falling Short of diStal margin of lamella; carpocerite with diSto-lateral tooth.
Mandible with inciSor and molar proceSS widely Separated (
Fig. 3A
), palp abSent, inciSor with three teeth; molar ridged. Maxillule (
Fig. 3B
) with two enditeS; lower endite diStally with plumoSe Setae; upper endite with cuSpidate and pappoSe Setae; palp bilobed, non-SetoSe. Maxilla (
Fig. 3C
) with Single endite, terminally with Simple Setae; endopod Short, diStally recurVed; Scaphognathite large. FirSt maxilliped (
Fig. 3D
) with well-deVeloped exopodS; enditeS Separated oVer entire width; endopod well-deVeloped; caridean lobe broad. Second maxilliped (
Fig. 3E
) with Single podobranch, endopod without diStinguiShing featureS; exopodS well-deVeloped. Third maxilliped (
Fig. 3F
) pediform, elongate; endopod four-Segmented, two arthrobranchS preSent, dorSal one with reduced lamellae.
FirSt pereiopod Slender (
Fig. 4A
), oVer-reaching Scaphocerite by diStal half of propoduS; meruS about 2.0 x length of iSchium; carpuS of equal length to meruS; carpo-propodal bruSh preSent, but reduced (
Fig. 4B
); chelae about 0.75 x length of carpuS, fingerS of equal length to palm, both ending in Strong tooth; lower Surface of palm and fixed finger with well-deVeloped tuft of Serrate Setae; tipS of both fingerS with tuft of Simple Setae.
FIGURE 2.
Eurindicus bhugarbha
gen nov., sp. nov.
A) Carapace, frontal region, lateral vieW; B) same, dorsal vieW; C) frontal margin, lateral vieW; D) sixth pleonite, lateral vieW; E) antennule; F), same, detail; G) same, detail; H) scaphocerite; I) pereon, fifth sternite; J) telson; K) uropod; L) same, protopod; M) same, diaresis. All from paratype, male (pocl 3.0 mm), BNHS CAR 2.
FIGURE 3.
Eurindicus bhugarbha
gen nov., sp. nov.
A) mandible; B) maxillule (coxal endite separated during dissection); C) maxilla; D) first maxilliped; E) second maxilliped; F) third maxilliped. All from paratype, male (pocl 3.0 mm), BNHS CAR 2.
FIGURE 4.
Eurindicus bhugarbha
gen nov., sp. nov.
A) first pereiopod; B) same, carpo-propodal brush; C) second pereiopod, minor; D) second pereiopod, major; E) same, chela; F) third pereiopod; G) fourth pereipod; H) fifth pereiopod, propodus and dactylus. All from paratype, male (pocl 3.0 mm), BNHS CAR 2.
Second pereiopodS, robuSt, Subequal, Similar (
FigS. 4 C–D
), oVer-reaching Scaphocerite by diStal half of propoduS; meruS Subequal in length to iSchium; carpuS Subequal in length to meruS; anterior margin without teeth; chelae about 3.0 aS long aS carpuS; fingerS about 0.70 x length of palm, both ending in Single tooth; proximal margin of cutting edge of fixed finger with two, low teeth; Single tooth on moVeable finger (
Fig. 4E
).
Third to fifth pereiopodS Similar in Shape and Size. Third pereiopod (
Fig. 4F
) oVer-reaching Scaphocerite by entire length of propoduS; meruS about 1.4 x length of iSchium; carpuS about 0.6 x length of meruS, without cuSpidate Setae on diStoVentral margin; propoduS about 1.7 x length of carpuS, lower margin with 5–6 Spiniform Setae, Scattered along margin; dactyl (
Fig. 5C
) about 0.4 x length of propoduS, bifid, unguiS not clearly demarcated. Fourth pereiopod (
Fig. 4G
) Similar to third, oVer-reaching Scaphocerite by diStal third of propoduS; lower margin of propoduS with 5–6 Spiniform Setae; carpuS without cuSpidate Setae on diStoVentral margin; dactyluS (
Fig. 5D
) Similar to third. Fifth pereiopod (
Fig. 4H
) Similar, oVer-reaching antennal Scale by diStal two-thirdS of propoduS; propodal cleaning bruSh with two rowS of pappoSe Setae; diStal Setae more robuSt.
TelSon (
Fig. 2J
) broad, about 1.6 x aS long aS wide, reaching to 0.7 x uropod length; dorSal Surface with two, marginally placed pairS of SpineS; anterior pair at 0.3 of telSon length; poSterior pair of equal Size, at 0.6 of telSon length; poSterior margin broadly rounded, anteriorly conStricted, laterally with two pairS of SpineS, medial pair about 2.5 x length of lateral pair; diStal margin with annulated, plumoSe Setae.
FIGURE 5.
Eurindicus bhugarbha
gen nov., sp. nov.
A) first pleopod; B) second pleopod; C) third pereiopod, dactylus; D) fourth pereiopod, dactylus; E) fifth pereiopod, dactylus. All from paratype, male (pocl 3.0 mm), BNHS CAR 2.
Uropod (
Fig. 2K
) broad; protopod with weakly deVeloped lateral expanSion (
Fig. 2L
), tip with 4–5 elongate, Simple Setae; endopod and exopod equal in length; diareSiS complete, but weaker medially, furniShed with Single cuSpidate Seta (
Fig. 2M
) at lateral angle; marginS of endopod and exopodS with annulate, plumoSe Setae.
FirSt pleopod (male) (
Fig. 5A
) with elongate protopod; exopod about 1.4 x length of endopod; appendix interna preSent; diStally with 4–5 cincinulli; baSal margin of endopod with two coupling hookS. Second pleopod (male) (
Fig. 5B
) with elongate protopod, exopodS Slightly longer than endopod; endopod with appendiceS internae and maSculine; appendix maSculina longer than interna, lateral and diStal margin with elongate, Simple Setae; baSal margin of endopod with two coupling hookS. Third to fifth pleopod (male) with well-deVeloped endopod; appendix interna preSent, Shorter than endopod.
Branchial formula. Podobranch on Second maxilliped; epipodS on maxillipedS 1–2; exopodS on maxillipedS 1– 3; two arthrobranchS on maxilliped 3; Single pleurobranch on pereiopodS 1–5.
Colour pattern.
The SpecieS iS largely colourleSS and tranSparent, but with a yellow-orange hue on the body (
Fig. 6
).
FIGURE 6.
Eurindicus bhugarbha
gen nov., sp. nov.
Holotype, male (pocl 3.2 mm), BNHS CAR 1. A) Whole animal shortly after capture; B) carapace and frontal region; C) rostrum.
Etymology.
The SpecieS name ‘
bhugarbha
’ meanS underground in Malayalam, the natiVe language Spoken in the State of
Kerala
in
Southern
India
, uSed aS a noun in appoSition.
Habitat.
A priVate homeStead well,
8.64 m
deep, which haS been regularly uSed Since 1994 for drinking water and home-baSed irrigation purpoSeS. The well iS compoSed of lateritic Soil for the initial depth of up to 5 meterS followed by clay. Water temperature in the well waS 26±1°C.
Distribution.
Currently only known from the
type
locality in Puthiyatheru,
Kannur
DiStrict,
Kerala
State,
Southern
India
. It iS not known whether the SpecieS occurS in adjoining wellS or iS further diStributed in the aquifer.
Systematic remarks.
See under
Eurindicus
gen. nov.