Fridericia ratzeli Lu & Xie & Zhang 2018, sensu stricto
Creators: name: Lu, Yajing
name: Xie, Zhicai
name: Zhang, Junqian
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Clitellata
Enchytraeida
Enchytraeidae
Fridericia
Fridericia ratzeli

description: Fridericia ratzeli (Eisen, 1872) sensu stricto
(FigURES 1, 2)
Enchytraeus ratzeli Eisen, 1872.
Fridericia ratzeli (Eisen). Michaelsen 1889; Nielsen & Christensen 1959; Schmelz 2003; Schmelz & Collado 2010.
Fridericia canadensis Dash, 1972.
Fridericia eiseni Dózsa-Farkas, 2005.
See Schmelz (2003) for further synonymies.
Examined material. XZO201510003, XZO201510001, XZO201510002, YNO201512001, all FUllY maTURE SPEcimENS, STaiNEd, WhOlE-mOUNTEd, cOllEcTEd aT SiTES 2 aNd 3; ca. 20 SPEcimENS PRESERVEd iN EiThER 10% FORmaliN OR 70% EThaNOl.
Description. MEdiUm SiZE. BOdY lENgTh 15–20 mm (18–22 mm iN ViVO). BOdY WidTh 250–500 Μm aT V (ca. 300–500 Μm iN ViVO), 300–700 Μm aT XII (ca. 550 Μm iN ViVO). BOdY cOlOR PalE-WhiTE iN ViVO. SEgmENT NUmbER 44–66. HEad POlE aT 0/I, lONgiTUdiNal SliT. DORSal PORES FROm VII backWaRdS. EPidERmal glaNd cEllS gRaY iN ViVO, cONSPicUOUS iN PREcliTEllaR SEgmENTS, 5–8 TRaNSVERSE ROWS PER SEgmENT (Fig. 2J). ChaETal FORmUla: 4,5,6,(7,8) – 4,5,6,(7,8): 6,(7,8) – 4,5,6,(7,8). ChaETaE STRaighT, WiThOUT NOdUlUS, WEaklY bENT PROXimallY, iN aSYmmETRic FaN- ShaPEd aRRaNgEmENT WiThiN a bUNdlE (Fig. 2L). LENgTh OF chaETaE gRadUallY iNcREaSiNg FROm II TO V, laRgEST aT V (Fig. 1A). VENTRal chaETaE 36–81 Μm iN lENgTh, 5–9 Μm iN WidTh. ChaETaE iN XII abSENT iN maTURE SPEcimENS. CliTEllUm ElEVaTEd SlighTlY iN XII–1 /2XIII, giRdlE-ShaPEd. HYalOcYTES aNd gRaNUlOcYTES iN dENSE PaTTERN, iRREgUlaR aRRaNgEmENT (Fig. 2E, F). SPERmaThEcal PORES PaiREd aT IV/V. TWO SEPaRaTE bURSal SliTS, T-ShaPEd, VENTRallY iN ThE middlE OF XII. ThREE SUbNEURal glaNdS PRESENT iN POSTcliTEllaR SEgmENTS, FROm XIII TO XV, ca. 98 Μm iN lENgTh aNd 78 Μm iN WidTh (Fig. 2H, K).
BRaiN iN 0/I, cONcaVE aNTERiORlY, aNd ROUNd OR TRUNcaTE POSTERiORlY ca. 160 Μm iN lENgTh aNd 100 Μm iN WidTh iN ViVO, 70–110 µm WidE aNd 125–180 µm lONg iN FiXaTiON cONdiTiON (Fig. 1B, Fig. 2M). DORSal VESSEl aRiSiNg FROm XX–XXI. BlOOd cOlORlESS. ThREE PaiRS OF PhaRYNgEal glaNdS PRESENT iN IV–VI, ThE FiRST PaiR cOmPaRaTiVElY laRgER WiTh dORSal cONNEcTiON, ThE OThERS Small aNd SEPaRaTEd dORSallY, TWO PaiRS OF VENTRal lObES iN V aNd VI (Fig. 2I). PaiREd OESOPhagEal aPPENdagES ORigiNaTiNg FROm III aNd EXTENdiNg aNd cONTORTiNg backWaRdS TO V, WiTh 6–7 bRaNchES (Fig. 1E, Fig. 2G). INTESTiNal diVERTicUla abSENT. ChlORagOcYTES bEgiNNiNg FROm VII backWaRdS, bROWNiSh, WEll-dEVElOPEd. ChYlUS cEllS USUallY iN XV–XVI. COElOmO-mUcOcYTES, ROUNd OR OVal, ca. 50–55 Μm iN ViVO (TYPE “c”), 25–37 Μm iN WidTh aNd 37–50 Μm iN lENgTh (Fig. 2N). LENTicYTES NUmEROUS, Small, OVal OR SPiNdlE-ShaPEd, 5– 6 Μm lONg aNd 1–1.5 Μm WidE. FOUR PaiRS OF PREcliTEllaR NEPhRidia FROm VII/VIII TO X/XI. NEPhRidial aNTESEPTalE cONSiSTiNg a NEPhROSTOmE aNd a FEW NEPhRidial TiSSUES (Fig. 1B). POSTSEPTalE 60–68 Μm lONg aNd abOUT 39–44 Μm WidE, WiTh aN EFFERENT dUcT aRiSiNg TERmiNallY.
SPERm FUNNElS WEll dEVElOPEd, PRESENT iN XI, cYliNdRical, gRadUallY TaPERiNg POSTERiORlY (Fig. 1F, Fig. 2A, B), 350–450 Μm lONg aNd 100–140 Μm WidE iN ViVO. COllaR aS WidE aS OR SlighTlY NaRROWER ThaN FUNNEl bOdY (ca. 15 Μm iN hEighT). HEadS OF SPERmaTOZOa abOUT 97 Μm lONg. VaS dEFERENS cONFiNEd TO XII, ShORT, NaRROW, WOUNd iN iRREgUlaR lOOPS VENTRallY, bETWEEN SPERm FUNNEl aNd malE PORE. SEmiNal VESiclE laRgE, OccUPYiNg X–XI. USUallY 1 Egg maTURE aT a TimE, almOST aS WidE aS WORm diamETER, WiTh SEVERal immaTURE EggS, PRESENT iN XII.
SPERmaThEca iN V–VI WiTh 2 EcTal glaNdS (30–50 Μm iN ViVO) aT Each EcTal ORiFicE (Fig. 2C, G). EcTal dUcTS ca. 350–400 Μm iN lENgTh aNd 24–30 Μm iN WidTh iN ViVO (Fig. 1C, Fig. C, D). AmPUlla ROUNd OR ONiON-ShaPEd (ca. 200–220 Μm iN ViVO, 88–103 Μm aFTER FiXaTiON), WiTh 6–8 ROUNd diVERTicUla OF VaRYiNg SiZE, 2 OF ThEm WElldEVElOPEd (ca. 75 Μm iN ViVO, 70 Μm aFTER FiXaTiON) aNd FillEd WiTh SPERmaTOZOa, ThE OThERS Small (ca. 30 Μm iN ViVO) aNd WiThOUT SPERmaTOZOa (Fig. 1C, Fig. 2C, D). ENTal dUcTS ShORT, UNiTEd bEFORE aTTachmENT TO OESOPhagUS iN VI.
Differential diagnosis. OUR SPEcimENS aPPaRENTlY bElONg TO Friderica ratzeli SENSU STRicTO (SchmElZ & COlladO 2010). Friderica ratzeli iS cONcEiVEd aS a hETEROgENEOUS SPEciES, aNd a lEaST iNclUdES TWO mORPhOlOgicallY diSTiNgUiShablE FORmS (ChalUPSký 1992, SchmElZ 2003). SchmElZ (2003) idENTiFiEd ThEm aS “ThE FiRST FORm cOmPRiSES laRgE SPEcimENS (UP TO 25 mm lONg aNd 0.8 mm WidE), Which POSSESS SPERmaThEcal diVERTicUla WiTh diSTiNcT lUmiNa, USUallY FillEd WiTh SPERm, a SPERmaThEcal EcTal dUcT ThaT WidENS cONSidERablY PROXimad, aNd a FaiRlY laRgE SUbNEURal glaNd iN XIII”, aNd “ThE SEcONd FORm cOmPRiSES SmallER SPEcimENS (UP TO 15 mm lONg aNd 0.5 mm WidE), Which POSSESS SPERmaThEcal diVERTicUla WiThOUT a diSTiNgUiShablE lUmEN, aN EcTal dUcT ThaT WidENS ONlY SlighTlY PROXimad, aNd ThREE SmallER SUbNEURal glaNdS iN XIII, XIV aNd XV”. ChalUPSký (1992) TENTaTiVElY idENTiFiEd ThE FORmER aS F. dura (EiSEN, 1879) aNd ThE laTTER aS F. ratzeli SENSU STRicTO. SchmElZ aNd COlladO (2010) TREaTEd ThEm aS TWO Valid SPEciES, F. ratzeli SENSU STRicTO aNd F. dura. OUR SPEcimENS aRE clOSE TO F. ratzeli SENSU STRicTO bY almOST TaXONOmical TRaiTS OF chaETal NUmbER PER bUNdlE, bRaNchEd OESOPhagEal aPPENdagES, cOElOmOmUcOcYTES TYPE, SUbNEURal glaNdS PRESENT iN XIII–XV, SPERmaThEca WiTh TWO EcTal glaNdS, aNd amPUlla diSTallY SURROUNdEd bY 6–8 glObUlaR diVERTicUla WiTh laRgE lUmEN. HOWEVER, OUR SPEcimENS diFFERS FROm F. ratzeli SENSU STRicTO bY ThE PRESENcE OF FOUR PaiRS OF PREcliTEllaR NEPhRidia (FiVE PaiRS iN F. ratzeli SENSU STRicTO). ThiS iS ThE FiRST REcORd OF ThE SPEciES FROm ChiNa.
description: Published as part of Lu, Yajing, Xie, Zhicai & Zhang, Junqian, 2018, Preliminary taxonomical investigation of soil enchytraeids (Clitellata, Enchytraeidae) from south region of Tibet, China, pp. 395-410 in Zootaxa 4496 (1) on pages 396-399, DOI: 10.11646/zootaxa.4496.1.29, http://zenodo.org/record/1446917