Org. Divers. Evol. 6, Electr. Suppl. 8: 1 - 20 (2006) © Gesellschaft für Biologische Systematik URL: http://www.senckenberg.de/odes/06-08.htm URN: urn:nbn:de:0028-odes0608-9

The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in southern Luzon, Philippines

Samuel W. James

Natural History Museum and Biodiversity Research Center, Dyche Hall, 1345 Jayhawk Drive, University of Kansas, Lawrence, KS 66045, USA e-mail: [email protected]

Received 2 December 2004 • Accepted 11 August 2005

Abstract

An earthworm biodiversity survey of the Philippines has yielded 14 new species of the perichaetine megascolecid genus Pleionogaster, previously known from only a few species from scattered Philippine locations. Bicol, the southern peninsula of Luzon, has intact forests on several isolated volcanic peaks and other remote areas. Collections made in these forests yielded the following new species, here presented by type location: Mt. Malinao, Pleionogaster albayensis, P. bicolensis, P. castilloi, P. malinaoensis, P. tiwiensis; Mt. Isarog, P. ffitchae, P. isarogensis; Mt. Bulusan, P. bulusanensis, P. hongi, P. sorsogonensis; Catanduanes Island, P. nautsae, P. viracensis; Caramoan Peninsula, P. caramoanensis, P. nillosae. Most of the species were found only in the neighborhood of the type locality, but P. bicolensis occurs in two locations in northern Bicol. Intraspecific variation in P. castilloi was observed between northern and southern flanks of Mt. Malinao. The impor- tance of several previously overlooked Pleionogaster traits is demonstrated by their homogeneity within species reported here. Keywords: Pleionogaster; Megascolecidae; Clitellata; Philippines; Luzon; Bicol

Introduction The perichaetine megascolecid genus Pleionogaster about its placement in that group. Its members have Michaelsen, 1892 has long been known from a few iso- a reduced esophageal gizzard in viii, all the anterior lated collections made in the Philippines during the last septa are present, and these are generally muscular an- two centuries (Easton 1979; James 2004), but its range terior of 9/10 or 10/11. There are paired meganephri- and diversity remained unknown. In early 2001 the au- dia in the intestinal segments, but not elsewhere; these thor and a field team set out to conduct the first organi- are connected to paired longitudinal ducts flanking the zed collecting of earthworm material from the Philip- dorsal blood vessel. In addition there are regular ranks pines, and discovered many species of Pleionogaster of micronephridia opening to corresponding rows of in all parts of the island of Luzon, including Catandu- nephridiopores, again in the intestinal segments. Mi- anes, an island united with Luzon at Pleistocene low cronephridia are present in the anterior segments but sea levels (Heaney 1985; 1993). This paper is one of are placed differently. The intestine is supplied with a series planned on new earthworm species discove- several gizzards posterior to xxiv, followed by an aty- red by the Philippines Terrestrial Annelid and Gastro- phlosolate section of intestine up to 25 segments long, pod Survey (PTAGS). Here I report the Pleionogaster at the end of which is a constriction and the typhlosolar species found in Bicol, a long southern peninsula of origin, if a typhlosole is present. The supra-esophageal Luzon,plus Catanduanes Island, composed of lowland vessel extends posteriorly past the heart segments to plains dotted with dormant and active volcanoes. xvii in most cases, and the vessels returning blood from Pleionogaster is an interesting group of earthworms, the clitellar region (posterior latero-parietals) are from from the standpoint of the systematics of the Phereti- one to four pairs in segments xiv–xvii. In some cases ma complex (sensu Sims and Easton 1972) of the Me- the posteriormost pair of these vessels is connected to gascolecidae. Several of its characteristics are unique paired longitudinal vessels extending many segments among the genera of the complex, raising questions back on the body wall. Most of these features have

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 2 been noted in older works on the genus, but some are molecular phylogenetic studies, and were archived at reported here for the first time. –20 ºC. All material was scored for external characters, No other genera in the Pheretima complex share any drawings made by way of a drawing tube, and inter- of the unusual features of Pleionogaster, and neither nal anatomy studied by dorsal dissection. Setal counts do any other megascolecid genera found in the regi- were made over 1 mm each of a dorsal, lateral and on comprising the Philippine and Indonesian archi- ventral segmental equator arc, averaging these counts, pelagoes and mainland Southeast Asia west through and multiplying the average by the estimated circum- Thailand. This poses a biogeographic and systematic ference of the segment. This was necessary due to the puzzle, the solving of which will require additional ex- extremely large numbers of setae (up to 300) crowded ploration. For now, the most likely location of related into the anterior setal rings. genera seems to be Australia, where Anisogaster Blake- Collecting site data include the acronym PTAGS more, 2000, Eastoniella Jamieson, 1977, Gastrodrilus (Philippine Terrestrial Annelid and Gastropod Survey) Blakemore, 2000, Hickmaniella Jamieson, 1974, Pseu- followed by a location number that uniquely identifies a docryptodrilus Jamieson, 1972, and Pseudonotoscolex location in the survey. Latitude and longitude are given Jamieson, 1971 share some characteristics with Pleio- in degrees and decimal minutes. Elevations were read nogaster (Jamieson 2000). The Indian genus Lampito from a GPS unit (Magellan Map410) if sufficient sa- Kinberg, 1866 has a similar arrangement of post-clitel- tellites were detectable, or from an altimeter. The map lar meganephridia and ducts (Gates 1972) datum used in the GPS readings was Luzon. Collectors Ecologically, members of Pleionogaster are mostly listed are those working at the respective site. endogeic, with generally long and slender, rarely pig- Holotypes of the new species are deposited in the mented bodies, and always found in the soil, never in National Museum of the Philippines Annelid Collec- litter or arboreal habitats. Some of the larger species in tion (NMA), P. Burgos St., Manila, Philippines. Ad- which the anterior ends are darkly pigmented may be ditional depositories: KUNHM = Kansas University anecic. Natural History Museum, Lawrence, Kansas USA; UPLBMNH = University of the Philippines Los Baños Methods and material Museum of Natural History, College, Laguna, Philip- On the upper slopes of the Bicol volcanoes lie the re- pines. maining primary montane and mossy forests of the area, and these were given priority in collecting. Collections Taxonomic section were also carried out in two low-elevation sectors in Clitellata: Megascolecidae Rosa, 1891 some relatively undisturbed forest on Catanduanes Is- Genus Pleionogaster Michaelsen, 1892 land and the nearby Caramoan Peninsula. Earthworms Perichaeta Beddard, 1886: 298 (in part). were collected by digging and handsorting soil, sear- Pleionogaster Michaelsen, 1892: 247; Beddard ching organic soil and root mats from the tops of boul- (1895: 433), Michaelsen (1896: 198), Easton (1979: ders, logs, roots and branches, dissecting epiphytes, 114), James (2004). primarily arboreal ferns, and searching the leaf axils of Plionogaster Michaelsen, 1900: 210; Stephenson palms and Pandanaceae. All specimens examined for (1930: 840), Stephenson (1933: 923), Gates (1943: this paper were recovered from mineral soil, not from 105), Jamieson (1971: 82). organic soil horizons, organic mats or other suspended soils, or plants. Type species. Pleionogaster jagori Michaelsen, Photographs were taken live of as many different 1892 (Easton 1979). species as could be distinguished in the field by in- Diagnosis. Perichaetine Megasolecidae with larger spection with the unaided eye. Additional photomic- numbers of setae in the head segments than in post–cli- rographs were taken in the laboratory using a Nikon tellate segments, a reduced esophageal gizzard in viii, Coolpix 995 digital camera fitted to an adapter moun- intestinal gizzards in the region xxiv–xxx, paired ente- ted on the phototube of a Leica M5 stereomicrosco- roic stomate meganephridia and regular ranks of exoic pe. Specimens were killed in 50% ethanol and fixed in micronephridia in post-clitellate segments, and a single 10% formaldehyde in the field. After at least 48 hours pair of racemose prostates whose ducts are united with fixation they were rinsed in three changes of tap water the vasa deferentia near the ental end of the duct. All with at least 12 hours between changes, and transferred known species have paired spermathecae in segments to 80% ethanol. This removes residual formaldehyde, viii and ix. reduces health hazards to those working with the speci- Remarks. James (2004) discussed synonymy issues mens, and may reduce DNA degradation. Duplicate raised by Easton (1979) and made some changes to the sets of specimens were preserved in 95% ethanol for genus definition in Easton (1979).

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 3

Pleionogaster tiwiensis n. sp. se attached to tubules adherent to either side of dorsal (Fig. 1A, B) vessel. Ovaries and funnels free in xiii, spermathecae paired Etymology. Named after Tiwi, the municipality clos- in viii, ix without nephridia on ducts; each spermatheca est to the type locality. with club-shaped ampulla, ampulla not sharply demar- Type material. Holotype (NMA004134): adult, ked from duct; simple club-shaped diverticulum joins PTAGS 055, Albay Province, near Tiwi, montane for- duct near body wall (Figure 1B). Male sexual system est on north ridge of Mt. Malinao, 13° 25.98’ N, 123° holandric, testes and funnels enclosed in annular sacs 37.63’ E, 850m asl, 10 May 2001, leg. S.W. James & A. in x, xi, these sacs encompass hearts, seminal vesicles; Castillo. Paratypes (KUNHM 002175): 4 adults, col- seminal vesicles xi, xii small, acinous; vasa deferen- lecting data as for holotype. tia very small, travel up prostatic ducts, adherent to Description. Unpigmented, body 94–103 mm x 3.1– surface thereof until entering duct at most half-way to 3.5 (vii), 2.7–3.7 mm (xv), 3.3–3.9 mm (xxv); 215–285 male pore; each prostate racemose two- to four-lobed, segments, some specimens with regenerated segments; occupying xviii; with muscular duct; copulatory bursae body cylindrical in cross-section; segments x–xiii bian- lacking. nulate, postclitellar segments faintly biannulate in ante- rior half of body. First dorsal pore 11/12 or 12/13; sper- Remarks. The efferent latero-parietal vessels of mathecal pores paired in 7/8, 8/9, 0.08 circumference most Megascolecidae are formed from the coalescence apart, female pore single in xiv, male pores crescentic of small vessels on the body wall of clitellar segments paired in xviii on raised porophores, 0.12 circumfer- to a single pair of vessels that join the extraesophageal ence apart, 5–6 setae between male pores. Setae regu- vessels or the esophageal wall, usually in the region of larly distributed around segmental equators; estimated segments xiii–xvi. In P. tiwiensis this arrangement is at 210 setae on vii, 114 setae on xxv; in vii no dorsal not found, but instead there are four such paired con- gap, in xx ZZ:YZ = 2–3, ventral gap AA:AB = 2. Cli- nections to the extra-esophageals from the body wall of tellum annular 1/2xiii, xiv–1/2xvii; genital markings clitellar segments xiv–xvii. midventral broad pad xvii, paired presetal in line with Pleionogaster tiwiensis is one of many species with male pores on xviii, narrow elongate midventral over four intestinal gizzards in xxvii–xxx (Table 1). Among equator, presetal portion of xx, xxi, midventral epider- those it has similar numbers of micronephridia in the mal thickenings of xxii–xxiv (Figure 1A). Body wall intestinal segments to P. viracensis and P. isarogensis. slightly depressed between male pores. Nephridiopores However, P. viracensis is pigmented and has a more visible as gaps in setal rings of postclitellar segments, posterior intestinal constriction, P. isarogensis lacks apparently 6–10 pores per segment but not always in paired genital markings, has a more posterior intesti- regular rows. nal origin, a more anterior intestinal constriction, and Septa 5/6–8/9 thick, muscular, 9/10 thinner, remain- a single pair of latero-parietal vessels in xv rather than der membranous. Weak gizzard in viii with typical iri- four pairs. descent outer wall but flaccid, esophagus vascularized, with low villous discontinuous vertical folds xiii–xvii, Pleionogaster albayensis n. sp. valvular xviii, intestinal origin xix, no caeca; thick in- (Fig. 1 C, D) testinal gizzards xxvii–xxx (4), xxv–xxviii (1); typhlo- Etymology. Named after the province of Albay in sole xlvii–lxx, simple fold, 0.1–0.15 lumen diameter. which the species was found. Intestine heavily vascularized xx–xxvii, less vasculari- Type material. Holotype (NMA 004135): adult, zed xxxi–xlv, xlvi; internal texture changes from rugo- PTAGS 055, Albay Province, near Tiwi, montane for- se to smooth xlv, xlvi. est on north ridge of Mt. Malinao, 13° 25.98’ N, 123° Hearts x–xiii esophageal, commissural vessels v–ix 37.63’ E, 850m asl, 10 May 2001, leg. S.W. James & lateral. Supra-esophageal vessel x–xvii, efferent parie- A. Castillo. to-esophageal vessels lacking, but vessels connecting Description. Slight purplish-brown anterior-dorsal extraesophageal vessel to body wall present in each of tint, dusky strip along mid-dorsal line, otherwise un- xiv–xvii, extra- esophageal vessels from vi to xiii, in pigmented, body 94 mm x 2.7–3.2 mm (vii), 2.6–2.9 xiii fuse to single midventral vessel on ventral esopha- mm (xv), 3.0–3.7 mm (xxv); 159 + > 60 regenerated geal wall, entering esophageal wall xviii. segments, regenerates very small and asetal, thus hard Nephridia present as peptonephridia on anterior to count; body cylindrical in cross-section; segments faces of 4/5, 5/6, micronephridia preseptal clustered viii, ix biannulate, x–xiii triannulate, anterior half of around commissural vessels vi–ix, on body wall the- postclitellar segments triannulate. First dorsal pore reafter; from xix 6–10 micronephridia per segment, 2 12/13; spermathecal pores paired in 7/8, 8/9, 0.2 cir- meganephridia per segment from xix posteriorly, the- cumference apart; female pore single in xiv, male pore

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 4 openings crescentic, paired in xviii on porophores tilt- constriction, a more anterior intestinal origin, and the ed posteriorly, 0.18 circumference apart, 12 setae be- first two lack midventral genital markings (Table 1). tween male pores. Setae regularly distributed around Pleionogaster bicolensis n. sp. segmental equators; estimated at 148 setae on vii, 85 setae on xxv; no dorsal or ventral gaps. Clitellum an- (Fig. 1E, F) nular xiv–xvii; genital markings paired presetal xvii, Etymology. Named after the province of Bicol in paired 17/18, paired 18/19 in depression posterior to southern Luzon, because the species was collected in male pores, paired 19/20, paired presetal xix, xx, un- several locations in this region. paired midventral presetal xix (Figure 1C). Nephrid- Type material. Holotype (NMA 004136): adult, iopores visible as gaps in setal rings and longitudinal PTAGS 056, Albay Province, Barangay Jarod, upper musculature of postclitellar segments, 12 pores per montane forest on south ridge of Mt. Malinao, 13° segment in regular rows. 23.96’ N, 123° 37.16’ E, 1030m asl, 11 May 2001, leg. Septa 5/6–8/9 thick, muscular, 9/10 thinner, remain- S.W. James & A. Castillo. Paratypes: one adult (KUN- der membranous. Weak gizzard in viii with typical HM 002176), one adult (UPLBMHN Z-NS-0083); col- iridescent outer wall but flaccid, esophagus valvular lecting data as for holotype. xix, intestinal origin xx, no caeca; thick intestinal giz- Other material. KUNHM 002177: 1 adult, PTAGS zards xxvii–xxx; typhlosole xlvii–lxxiii, simple low 055., Albay Province, near Tiwi, montane forest on fold. Intestine internal texture changes from rugose to north ridge of Mt. Malinao, 13° 25.98’ N, 123° 37.63’ smooth xlv, coelomic fluid rich in oil within intestinal E, 850m asl, 10 May 2001, leg. S.W. James & A. Cas- segments. tillo. UPLBMNH Z-NS-0084: 1 adult, PTAGS 121, Hearts x–xiii esophageal, commissural vessels v–ix Camarines Norte Province, Caramoan Peninsula, low- lateral. Supra-esophageal vessel xi–xvii, efferent pari- elevation forest on karst, 13° 44.40’ N, 123° 54.38’ E, eto-esophageal vessels lacking, but vessels connecting 245m asl, 21 May 2001, leg. Y. Hong, M. Levi, P. Nil- extraesophageal vessel to body wall present in each of los. KUNHM 002178: 2 adults, PTAGS 122, Cama- xiv–xvii, extra- esophageal vessels from vi to xiii, in rines Norte Province, Caramoan Peninsula, low-eleva- xiii fuse to single midventral vessel on ventral esopha- tion forest on karst, 13° 45.29’ N, 123° 53.81’ E, 346m geal wall, entering esophageal wall xviii. asl, 22 May 2001, leg. Y. Hong, M. Levi, P. Nillos. Nephridia present as peptonephridia on anterior Description. Deep brown anterior dorsal pigmen- faces septa 4/5/6, micronephridia preseptal clustered tation, body 155–293 mm x 5.5–6 mm (vii), 5.6–6.6 around commissural vessels vi–ix, on body wall the- mm (xv), 5.6–6.8 mm (xxv); 340–370 segments, most reafter; from xix 12 micronephridia per segment, 2 specimens amputees; body cylindrical in cross-section; meganephridia per segment from xix posteriorly, the- segment xi biannulate, triannulate xii–xxx exclusive of se attached to paired tubules adherent to either side of clitellum. First dorsal pore 12/13; spermathecal pores dorsal vessel. paired in 7/8, 8/9, 0.17 circumference apart, asetal sec- Ovaries and funnels free in xiii, spermathecae paired tions ventrally near spermathecal pores viii, ix; female in viii, ix without nephridia on ducts; each spermatheca pore single in xiv, male pore openings paired in xviii with elongate club-shaped ampulla; simple club-shaped on porophores tilted posteriorly into sunken male field diverticulum joins duct near body wall on medial side zone, 0.17 circumference apart, 8–10 setae between rather than usual lateral side, slightly shorter than am- male pores. Setae regularly distributed around seg- pulla; no differentiation of duct from ampulla within mental equators; estimated at 130–220 setae on vii, coelom. (Figure 1D). Male sexual system holandric, 132–140 setae on xxv; no ventral gaps, dorsal gaps ZZ: testes and funnels enclosed in annular sacs in x, xi, the- YZ 2:1. Clitellum annular xiv–1/2xvii; genital mark- se sacs encompass hearts, seminal vesicles; sacs for- ings paired presetal xvii, xix; paired 17/18 (Figure 1E). med of membranes connecting septa 9/10 and 10/11, Nephridiopores visible as gaps in setal rings and longi- 10/11 and 11/12; seminal vesicles xi, xii large, dense, tudinal musculature of postclitellar segments, 12 pores acinous; vasa deferentia small, adherent to ental half of per segment in regular rows. prostatic duct, then fuse with duct; few micronephri- Septa 5/6–9/10 thick, muscular, others membranous. dia surrounding duct-body wall contact; each prostate Weak gizzard in viii with typical iridescent outer wall racemose four-lobed, occupying xviii; with muscular but flaccid; esophagus valvular xviii, intestinal origin duct; copulatory bursae lacking. xix or xx, no caeca; thick intestinal gizzards xxvii–xxx; Remarks. Other species with four intestinal gizzards typhlosole lacking. Intestine internal texture changes in xxvii–xxx and with dark pigmentation are P. bico- from rugose to smooth at intestinal constriction lvii. lensis, P. ffitchae and P. viracensis. All of these have Hearts xi–xiii esophageal, x lateral, commissural more setae per segment, a more posterior intestinal vessels v–ix lateral. Supra-esophageal vessel xi–xvii,

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 5 efferent parieto-esophageal vessels from body wall of 0.17 circumference apart, 20 setae between male pores; xv–xviii, intestinal segments to extraesophageal ves- clitellum not developed. Setae regularly distributed sels in xv, segmental parietal vessel from body wall of around segmental equators; estimated 200 setae on vii, xiv to extraesophageal vessels xiv; extra- esophageal 144 setae on x, 120 setae on xxv; no dorsal, ventral vessels ventral-lateral to gut vi–xii, ventral to esopha- gaps. Genital markings paired presetal xvii, postsetal gus xiii–xviii, fuse to one midventral vessel xviii, en- xvii, paired presetal xix–xxi, all just medial to line of ters esophageal wall at esophageal valve. male pores (Figure 1G). Nephridiopores visible as gaps Nephridia present as peptonephridia on anterior in setal rings, longitudinal musculature of postclitellar faces septa 4/5/6, micronephridia preseptal clustered segments, 14 pores per segment in regular rows. around commissural vessels vi–xi, on body wall the- Septa 5/6–8/9 thick, muscular, 9/10 thinner, muscu- reafter; from xviii 12 micronephridia per segment, lar, remainder membranous. Weak gizzard in viii with these connected to tubular sinus with connections to typical iridescent outer wall but flaccid, esophagus nephridiopores; 2 meganephridia per segment from xix valvular xix, intestinal origin xx, no caeca; thick intes- posteriorly, these attached to paired tubules adherent to tinal gizzards xxvii–xxx; typhlosole lacking; intestine either side of dorsal vessel. constricted lv, thereafter coated with brown chlorago- Ovaries and funnels free in xiii, spermathecae paired gen layer. in viii, ix without nephridia on ducts; each spermathe- Hearts x–xiii lateral-esophageal with very small con- ca with horn-shaped ampulla thinner-walled than stout nections to dorsal vessel, commissural vessels vii–ix muscular duct; simple club-shaped diverticulum joins lateral; supra-esophageal vessel x–xvii, extra-esopha- duct near body wall, slightly shorter than spermathecal geal vessels not traceable past viii. duct (Figure 1F). Male sexual system holandric, tes- Nephridia present as peptonephridia on anterior tes and funnels enclosed in horseshoe-shaped sacs in faces septa 4/5/6, micronephridia preseptal clustered x, xi, these sacs encompass hearts, seminal vesicles; around commissural vessels vi–ix, on body wall the- sacs formed of membranes connecting septa 9/10 and reafter; from xix 14 micronephridia per segment, two 10/11, 10/11 and 11/12; seminal vesicles xi, xii small, meganephridia per segment from xix posteriorly, these acinous; vasa deferentia slender, non-muscular; each attached to paired ureters adherent to either side of dor- prostate racemose rounded mass occupying xviii; with sal vessel. thick muscular duct; copulatory bursae lacking. Ovaries and funnels free in xiii, spermathecae paired Remarks. Among Pleionogaster with four intestinal in viii, ix without nephridia on ducts; each spermathe- gizzards in xxvii–xxx and dark pigmentation, P. bico- ca blunt lanceolate ampulla, poorly differentiated duct; lensis is most similar to P. ffitchae (Table 1). The lack narrow digitate diverticulum half or less length of main of a typhlosole, the more posterior intestinal constric- spermathecal axis joins duct near body wall (Figure tion, and the different array of latero-parietal vessels 1H). Male sexual system holandric, testes and funnels distinguish it from P. ffitchae. Distinction from P. al- enclosed in annular sacs in x, xi, these sacs encompass bayensis is discussed under that species. hearts, dorsal vessel, seminal vesicles; sacs formed of membranes connecting septa 9/10 and 10/11, 10/11 and Pleionogaster bulusanensis n. sp. 11/12; seminal vesicles xi, xii slender arcs; each pros- (Fig. 1G, H) tate racemose four- to five-lobed occupying xviii; duct Etymology. Named after the mountain on which the muscular; vas deferens slender, non-muscular, joins species was discovered. ental end of prostatic duct but visible within duct wall Type material. Holotype (NMA 004137): preclitel- over ental 2/3; copulatory bursae lacking. late adult, PTAGS 051, Sorsogon Province, Bulusan Remarks. The arc-shaped seminal vesicles are un- National Park, dipterocarp forest at Bulusan Lake, 12° usual. This species has a very large number of micro- 45.32’ N, 124° 05.34’ E, 360m asl, 3 May 2001, leg. nephridia per segment, relative to its body size. Other S.W. James, A. Castillo, K. James, P. James. Paratype small-bodied species reported here tend to have low (KUNHM 002179): 1 juvenile; collecting data as for numbers of micronephridia (4–6 per segment), whereas holotype. large numbers (10–12) have been found in large-bod- Description. Unpigmented, body 105 mm X 4.6 ied species such as P. bicolensis. This indicates that the mm (vii), 4.6 mm (xxv); 220 segments (anterior plus number of micronephridia may be size-related in most posterior fragments of same worm), 317 segments in but not all species. The genital markings are more nu- complete juvenile; body cylindrical. First dorsal pore merous and placed farther back in P. bulusanensis than 11/12; spermathecal pores paired in 7/8, 8/9, 0.15 cir- in most other species encountered so far. Of those un- cumference apart; female pore single, male pore open- pigmented Pleionogaster with four intestinal gizzards ings crescentic, paired in xviii on small porophores, in xxvii–xxx, it is the only species without a typhlosole

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 6 and has the posteriormost intestinal constriction (Table 1J). Male sexual system holandric, testes and funnels 1). enclosed in annular sacs in x, xi, these sacs encompass Pleionogaster hongi n. sp. hearts, dorsal vessel, seminal vesicles; sacs formed of membranes connecting septa 9/10 and 10/11, 10/11 and (Fig. 1I, J) 11/12; seminal vesicles xi, xii slender arcs; each prosta- Etymology. Named after Dr. Hong Yong, a Korean te racemose five-lobed occupying xviii; ectal 1/3 duct earthworm specialist who is part of the PTAGS re- muscular; vas deferens slender, non-muscular, joins search team. ental end of prostatic duct but visible within duct wall Type material. Holotype (NMA 004138): adult, over ental 2/3; copulatory bursae lacking. PTAGS 051, Sorsogon Province, Bulusan National Remarks. The closest morphologically is P. bulu- Park, dipterocarp forest at Bulusan Lake, 12° 45.32’ N, sanensis, but P. hongi has pink pigmentation (versus 124° 05.34’ E, 360m asl, 3 May 2001, leg. S.W. James, brown in the other pigmented Bicol species), half as A. Castillo, K. James, P. James. Paratype (KUNHM many setae between the male pores, an intestinal tran- 002180): adult; collecting data as for holotype. sition anterior to that of P. bulusanensis, and a typhlo- Description. Faint pink anterior dorsal pigment, sole (Table 1). body 84, 87 mm x 3–3.5 mm (vii), 2.9–3.2 mm (xv), 3–3.4 mm (xxv); 190, 189 + 49 regenerated segments; Pleionogaster ffitchae n. sp. body cylindrical. First dorsal pore 11/12; spermathecal (Fig. 2A, B) pores paired in 7/8, 8/9, 0.18–0.19 circumference apart; Etymology. Named after Jana ffitch, who as an un- female pore single, male pore openings crescentic, dergraduate student participated in the fieldwork and paired in xviii on small porophores facing posteriorly initial cataloguing of the 2001 expedition collections. in sunken male field, 0.18–0.19 circumference apart, 10–12 setae between male pores; clitellum xiv–1/2xvii, Type material. Holotype (NMA 004139): adult, annular. Setae regularly distributed around segmental PTAGS 060, Camarines Sur Province, montane forest equators; estimated 176 setae on vii, 104 setae on x, on Mt. Isarog, 13° 39.90’ N, 123° 21.89’ E, 1100m asl, 80 setae on xxv; no dorsal, ventral gaps. Genital mark- 14 May 2001, leg. Y. Hong, M. Levi, J. ffitch, P. Nillos, ings paired presetal xvii, 17/18, xix–xxi (Figure 1I). R. Abiada. Paratype (KUNHM 002181): adult; collec- Nephridiopores visible as gaps in setal rings, longitudi- ting data as for holotype. nal musculature of postclitellar segments, 12 pores per Other material. UPLBMNH Z-NS-0085: adult, segment in regular rows. PTAGS 066, Camarines Sur Province, lower montane Septa 5/6–8/9 thick, muscular, 9/10, 10/11 thinner, forest soils on Mt. Isarog, 13° 40.02’ N, 123° 21.16’ muscular, remainder membranous. Weak gizzard in E, 920m asl, 17 May 2001, leg. S.W. James, Y. Hong, viii with typical iridescent outer wall but flaccid, eso- M. Levi, J. ffitch, P. Nillos, D. Franke, R. Abiada, R. phagus valvular xix, intestinal origin xx, no caeca; in- Lazaro. KUNHM 002182: adult, PTAGS 069, Catan- testine vascularized xx–xxvi, thick intestinal gizzards duanes Province, low-elevation forest north of Baran- xxvii–xxx; typhlosole simple fold ¼ lumen diameter gay Summit, Buradan, 13° 46.0’ N, 124°16.0’ E, 275m xlvi–lxviii; intestine constricted 44/45, thereafter coa- asl, 22 May 2001, leg. S.W. James, P. James, J. James, ted with brown chloragogen layer. K. James, J. ffitch, A. Castillo. Hearts x–xiii esophageal, commissural vessels vi–ix Description. Medium milky brown dorsal pigment, lateral; supra-esophageal vessel x–xvii, extra-esopha- fading gradually towards tail, body 194, 170, 142 (am- geal vessels not traceable past viii, vessels from ventral putee) mm x 4.5–6 mm. (vii), 4.7–4.9 mm (xv), 4.6–5.8 esophagus xiv to body wall xv–xvii, paired longitudi- mm (xxv); 285, 352, 210 (amputee) segments; body nal vessels on body wall xviii–xxiv. cylindrical. First dorsal pore 11/12, 12/13; spermathe- Nephridia present as peptonephridia on anterior cal pores paired in 7/8, 8/9, 0.18–0.19 circumference faces septa 4/5/6, micronephridia preseptal clustered apart bordered by thick lips on trailing edges of vii, viii, around commissural vessels vi–ix, on body wall the- smaller lips on leading edges of viii, ix; female pore reafter; from xix 12 micronephridia per segment, two single, male pore openings crescentic, paired in xviii stomate meganephridia per segment from xix posteri- on small porophores facing posteriorly in sunken male orly, these attached to paired ureters adherent to either field, 0.16–0.17 circumference apart, 8 setae between side of dorsal vessel. male pores; clitellum xiv–1/2xvii, annular. Setae regu- Ovaries and funnels free in xiii, spermathecae paired larly distributed around segmental equators; estimated in viii, ix without nephridia on ducts; each sperma- 212–226 setae on vii, 150–170 setae on x, 100–110 se- theca cylindrical ampulla, poorly differentiated duct; tae on xxv; dorsal gaps variable ZZ = YZ, up to 2.5 club-shaped diverticulum half or less length of main YZ, ventral gaps AA:AB 1.5:1. Genital markings oval, spermathecal axis joins duct near body wall (Figure paired, presetal xvii, rectangular paired 17/18, oblong,

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 7 paired presetal xix–xxi (Figure 2A). Nephridiopores N, 124° 17.14’ E, 210m asl, 21 May 2001, leg. S.W. visible as gaps in setal rings, longitudinal musculature James, P. James, J. James, K. James, J. ffitch, A. Castil- of postclitellar segments, 12 pores per segment in regu- lo. Paratype (KUNHM 002183): adult; collecting data lar rows. as for holotype. Septa 5/6–9/10 thick, muscular, 10/11–16/17 tough Other material. UPLBMNH Z-NS-0086: adult, but transparent, remainder membranous. Weak giz- PTAGS 069, Catanduanes Province, low-elevation for- zard in viii with typical iridescent outer wall but flac- est north of Barangay Summit, Buradan, 13° 46’ N, cid, esophagus valvular xviii, intestinal origin xix, no 124°16’ E, 275m asl, 22 May 2001, leg. S.W. James, caeca; intestine vascularized xix–xxvi, thick intestinal P. James, J. James, K. James, J. ffitch, A. Castillo. gizzards xxvii–xxx; typhlosole simple fold 1/6 lumen UPLBMNH Z-NS-0087: adult, PTAGS 071, Catan- diameter 50/51 (1), liv (1)–lxxvii; intestine constricted duanes Province, lower riparian forest near Barangay xlix (1), 52/53 (1), thereafter coated with brown chlo- San Miguel, Pangabinan, 13° 54.50 N, 124° 11 E, ragogen layer. 212m asl, 23 May 2001, leg. S.W. James, J. ffitch, A. Hearts x–xiii esophageal, commissural vessels vi–ix Castillo. lateral; supra-esophageal vessel x–xvii, extra-esopha- Description. Medium brown anterior dorsal pig- geal vessels traced from iii–ix, then on ventral eso- ment, diminishing to mid-dorsal stripe in post-clitellar phageal surface x–xvi, segmental paired vessels from segments, body 107–140 mm x 4–4.6 mm (vii), 3.1–3.8 ventral esophagus xiii to body wall xiv–xvi, those of mm (xv), 4.2–4.5 mm (xxv); 260–279 segments; body xvi connect to paired longitudinal vessels on body wall cylindrical. First dorsal pore 11/12; spermathecal pores xviii–cv. paired in 7/8, 8/9, 0.13 circumference apart surrounded Nephridia present as peptonephridia on anterior by thickened area about 2 mm wide from 1/2vii–1/2ix; faces septa 4/5/6, micronephridia preseptal clustered female pore single, male pore openings crescentic, around commissural vessels vi–ix, on body wall the- paired in xviii on small porophores facing posteriorly reafter; from xix 12 micronephridia per segment, two in sunken male field, 0.16–0.17 circumference apart, stomate meganephridia per segment from xix posteri- 10 setae between male pores; clitellum xiv–1/2xvii, orly, these attached to paired ureters adherent to either annular. Setae regularly distributed around segmental side of dorsal vessel. equators; estimated 182–226 setae on vii, 150–160 se- Ovaries and funnels free in xiii, spermathecae paired tae on x, 138–146 setae on xxv; dorsal gaps variable ZZ in viii, ix without nephridia on ducts; each spermathe- = YZ, up to 1.5 YZ, no ventral gaps. Genital markings ca long lanceolate ampulla, duct of similar structure; oval, paired, presetal xvii, rectangular paired 17/18, short basally-attached diverticulum (Figure 2B). Male oblong, paired presetal xix–xxi, midventral at equator sexual system holandric, testes and funnels enclosed xviii (Figure 2C). Nephridiopores visible as gaps in se- in annular sacs in x, xi, these sacs encompass hearts, tal rings, longitudinal musculature of postclitellar seg- dorsal vessel, seminal vesicles; some individuals with ments, 10 pores per segment in regular rows. U-shaped dorsally open sac in x; sacs formed of mem- Septa 5/6–7/8 thick, muscular, 8/9 thinly muscled, branes connecting septa 9/10 and 10/11, 10/11 and 9/10–16/17 membranous. Weak gizzard in viii with 11/12; seminal vesicles xi, xii, thick ventral half, up- typical iridescent outer wall but flaccid, esophagus per portion slender arc; prostates racemose five-lobed valvular xviii, intestinal origin xix, no caeca; intestine occupying xviii; duct muscular; vas deferens slender, vascularized xix–xxvi, thick intestinal gizzards xxvii– non-muscular; copulatory bursae lacking. Genital mar- xxx; typhlosole very low fold lii–lxcii, full size by lvi; king glands sessile, dense xvii–xxi corresponding in intestine constricted lii (1), lvi (2), thereafter coated placement to external markings. with brown chloragogen layer. Remarks. Pleionogaster ffitchae is most similar to Hearts x–xiii esophageal, commissural vessels vi–ix P. bicolensis; differences are discussed under the latter lateral; supra-esophageal vessel x–xvii, extra-esopha- species. geal vessels traced from iii–ix, then on ventral eso- phageal surface x–xvii, segmental paired vessels from Pleionogaster viracensis n. sp. body wall to extra-esophageal vessels xiv; posterior la- (Fig. 2C, D) tero-parietals to extra-esophageals xv, these connect to Etymology. Named after Virac, the capitol city of paired longitudinal vessels on body wall xviii–cv. Catanduanes Province and the large town nearest to the Nephridia present as peptonephridia on anterior type locality. faces septa 4/5/6, micronephridia preseptal clustered Type material. Holotype (NMA 004140): adult, around commissural vessels vi–ix, on body wall the- PTAGS 068, Catanduanes Province, low-elevation reafter; from xix 10 micronephridia per segment, two forest near Barangay Summit, Buradan, 13° 43.60’ stomate meganephridia per segment from xix posteri-

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 8 orly, these attached to paired ureters adherent to either forest soils on Mt. Isarog, 13° 39.70’ N, 123° 22.07’ E, side of dorsal vessel. 1745m asl, 16 May 2001, leg. S.W. James, Y. Hong, Ovaries and funnels free in xiii, spermathecae paired M. Levi, J. ffitch, D. Franke, P. Nillos, R. Abiada, R. in viii, ix without nephridia on ducts; each spermathe- Lazaro. KUNHM 002188: 2 adults, PTAGS 066, Ca- ca broad club-shaped ampulla with very short slightly marines Sur Province, lower montane forest soils on differentiated muscular duct; short basally-attached Mt. Isarog, 13° 40.02’ N, 123° 21.16’ E, 920m asl, 17 diverticulum (Figure 2D). Male sexual system holan- May 2001, leg. S.W. James, Y. Hong, M. Levi, J. ffitch, dric, testes and funnels enclosed in annular sacs in x, P. Nillos, D. Franke, R. Abiada, R. Lazaro. xi, these sacs encompass hearts, seminal vesicles; slen- Description. Unpigmented, body 75–165 mm x der arcuate seminal vesicles xi, xii; prostates racemose 2.7–3.2 mm (vii), 2.2–3.0 mm (xv), 2.8–3.3 mm (xxv); three- to four-lobed occupying xviii; duct muscular; 275–294 segments; body cylindrical. First dorsal pore vas deferens slender, non-muscular; copulatory bursae 12/13; spermathecal pores paired in 7/8, 8/9, 0.09–0.11 lacking. circumference apart deep in furrows; female pore sin- Remarks. Among the brown-pigmented Pleionogas- gle, male pore openings crescentic, paired in xviii on ter with four intestinal gizzards in xxvii–xxx (Table 1), small porophores, 0.11–0.12 circumference apart, 4–8 P. viracensis is most similar to P. albayensis and P. setae between male pores; clitellum xiv–1/2xvii, annu- ffitchae. Pleionogaster albayensis has a lower number lar. Setae regularly distributed around segmental equa- of setae and more anterior locations of the intestinal tors; estimated 170–186 setae on vii, 110–120 setae on origin and constriction; P. ffitchae lacks mid-ventral x, 72–84 setae on xxv; asetal zones midventral in one genital markings, has more micronephridia per intes- or more of vii–ix. Genital markings oval, midventral, tinal segment, and three pairs of latero-parietal vessels presetal xvii, xix, xx (all), some with additional mid- rather than two. ventral GM xviii, epidermal thickenings ventral xxi, xxii; (Figure 2E). Nephridiopores visible as gaps in se- Pleionogaster isarogensis n. sp. tal rings, longitudinal musculature of postclitellar seg- (Fig. 2E, F) ments, 6 pores per segment in regular rows. Etymology. Named for Mt. Isarog, on which the spe- Septa 5/6–8/9 thick, muscular, 9/10 thinner, remain- cies was found over a wide elevational range. der membranous. Weak gizzard in viii with typical iri- Type material. Holotype (NMA 004141): adult, descent outer wall, esophagus valvular xviii, intestinal PTAGS 065, Camarines Sur Province, upper montane origin xx, no caeca; intestine vascularized xx–xxvi, forest soils on Mt. Isarog, 13° 39.75’ N, 123° 21.98’ E, thick intestinal gizzards xxvii–xxx with small vascu- 1500m asl, 16 May 2001, leg. S.W. James, Y. Hong, M. lar network on anterior thin-walled half of gut in each Levi, J. ffitch, P. Nillos, R. Abiada, R. Lazaro. Paratypes: giceriate segment; typhlosole simple fold 1/3 lumen 3 adults (KUNHM 002184), 4 adults (UPLBMNH Z- diameter for first ten segments, then only 1/6 lumen NS-0088); collecting data as for holotype. diameter from xli, xliii–lxxviii; intestine constricted Other material. UPLBMNH Z-NS-0089: 2 adults, 40/41 or 41/42. PTAGS 059, Camarines Sur Province, soils of mon- Hearts x–xiii esophageal, commissural vessels tane forest on Mt. Isarog, 13° 39.79’ N, 123° 21.79’ E, vii–ix lateral; supra-esophageal vessel x–xvii, extra- 1330m asl, 13 May 2001, leg. S.W. James, Y. Hong, esophageal with branch from body wall of xiv, effe- M. Levi, J. ffitch, D. Franke, P. Nillos, R. Abiada, R. rent posterior latero-parietal vessels travel up 15/16 Lazaro. KUNHM 002186: 2 adults, PTAGS 060, Ca- to extra-esophageal vessel in xvi, these connected to marines Sur Province, montane forest on Mt. Isarog, paired longitudinal vessels on body wall xviii–lviii; not 13° 39.90’ N, 123° 21.89’ E, 1100m asl, 14 May 2001, always visible past xxx. leg. Y. Hong, M. Levi, J. ffitch, P. Nillos, R. Abiada. Nephridia present as peptonephridia on anterior UPLBMNH Z-NS-0090: 1 adult, PTAGS 061, Cama- faces septa 4/5/6, micronephridia preseptal clustered rines Sur Province, mossy forest soils at summit of Mt. around commissural vessels vi–ix, on body wall there- Isarog, 13° 39.65’ N, 123° 22.28’ E, 1987m asl, 15 after; from xix 6–8 micronephridia per segment, two May 2001, leg. S.W. James, Y. Hong, M. Levi, J. ffitch, stomate meganephridia per segment from xix posteri- P. Nillos, R. Abiada, R. Lazaro. KUNHM 002187: 1 orly, these attached to paired ureters adherent to either juvenile, PTAGS 062, Camarines Sur Province, in or- side of dorsal vessel. ganic mats in mossy forest at summit of Mt. Isarog, 13° Ovaries and funnels free in xiii, spermathecae paired 39.65’ N, 123° 22.28’ E, 1987m asl, 15 May 2001, leg. in viii, ix without nephridia on ducts; each spermathe- S.W. James, Y. Hong, M. Levi, J. ffitch, P. Nillos, R. ca ovate ampulla; short basally-attached diverticulum Abiada, R. Lazaro. UPLBMNH Z-NS-0091: 2 adults, (Figure 2F). Male sexual system holandric, testes and PTAGS 064, Camarines Sur Province, upper montane funnels enclosed in annular sac in x, U-shaped sac

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 9 open dorsally in xi, these sacs encompass hearts, dor- ure 2G). Nephridiopores visible as gaps in setal rings sal vessel, seminal vesicles; sacs formed of membranes and longitudinal musculature of postclitellar segments, connecting septa 9/10,10/11; 10/11, 11/12; seminal apparently 10–12 pores per segment but not always in vesicles xi, xii, loosely acinous; prostates racemose regular rows. three- to four-lobed occupying xviii; ectal 1/3 duct Septa 5/6–8/9 thick, muscular, 9/10 thinner, remain- muscular; vas deferens slender, non-muscular; copula- der membranous. Weak gizzard in viii with typical tory bursae lacking. iridescent outer wall but flaccid, esophagus valvular Remarks. Compared to other unpigmented Pleiono- xviii, intestinal origin xix or xx (1), no caeca; thick in- gaster with four intestinal gizzards in xxvii–xxx, P. testinal gizzards xxv–xxix; typhlosole xlv, xlvii–lxiii, isarogensis has fewer setae per segment than P. bu- lxvii, lxxv simple fold, 0.1 lumen diameter. Intestine lusanensis and P. tiwiensis, more narrowly spaced internal texture changes from rugose to smooth xliii, male and spermathecal pores than P. bulusanensis, 43/44, xlvi. and consistently fewer micronephridia in the intesti- Hearts x–xiii esophageal, commissural vessels v–ix nal segments as well as a more anterior location of the lateral. Supra-esophageal vessel x–xvi, efferent parie- intestinal constriction than both those species (Table to-esophageal vessels lacking, but vessels connecting 1). While P. tiwiensis has both midventral and paired extraesophageal vessel to body wall present in each of genital markings, and P. bulusanensis has only paired xiv–xvii, extra- esophageal vessels from vi to xiii, in markings, P. isarogensis has only midventral genital xiii fuse to single midventral vessel on ventral esopha- markings. geal wall, entering esophageal wall xviii. Nephridia present as peptonephridia on anterior Pleionogaster malinaoensis n. sp. face septum 5/6, micronephridia preseptal clustered (Fig. 2G, H) around commissural vessels vi–ix, on body wall the- Etymology. Named after the mountain on which the reafter; from xix 10–12 micronephridia per segment, 2 material was collected. meganephridia per segment from xix posteriorly, the- Type material. Holotype (NMA 004142): adult, se attached to tubules adherent to either side of dorsal PTAGS 055, Albay Province, near Tiwi, montane for- vessel. est on north ridge of Mt. Malinao, 13° 25.98’ N, 123° Ovaries and funnels free in xiii, spermathecae paired 37.63’ E, 850m asl, 10 May 2001, leg. S.W. James & A. in viii, ix without nephridia on ducts; each spermatheca Castillo. Paratype (KUNHM 002189): adult; collecting with ovate ampulla differentiated from narrower duct; data as for holotype. simple club-shaped diverticulum joins duct near body Other material. KUNHM 002190: 2 adults, PTAGS wall, slightly longer than spermathecal duct (Figure 056, Albay Province, Barangay Jarod, upper mon- 2H). Male sexual system holandric, testes and funnels tane forest on south ridge of Mt. Malinao, 13° 23.96’ enclosed in annular sacs in x, xi, these sacs encompass N, 123° 37.16’ E, 1030m asl, 11 May 2001, leg. S.W. hearts, seminal vesicles; sacs formed of membranes James and A. Castillo. connecting septa 9/10 and 10/11, 10/11 and 11/12; se- Description. Unpigmented, body 97–110 mm x minal vesicles xi, xii small, acinous; vasa deferentia 2.8–3.2 mm (vii), 2.6–3.4 (xv), 3.5–4 mm (xxv); 227 slender, non-muscular; each prostate racemose multi- segments, most specimens amputees; body cylindrical lobed, occupying xviii; with slender muscular duct; in cross-section; segments x–xiii triannulate, postclitel- copulatory bursae lacking. lar segments faintly triannulate in anterior half. First Remarks. Other species with five gizzards in xxv– dorsal pore 12/13; spermathecal pores paired in 7/8, xxix are P. sorsogonensis and potentially P. castil- 8/9, 0.10 circumference apart, female pores single in loi from the same mountain (Table 2). Pleionogaster xiv, male pores crescentic paired in xviii on raised po- malinaoensis has more intestinal micronephridia and rophores, 0.09 circumference apart, 2–4 setae between more narrowly spaced male and spermathecal pores male pores. Setae regularly distributed around segmen- than those two species. Pleionogaster castilloi (see tal equators; estimated at 150–160 setae on vii, setal below) lacks paired genital markings; P. sorsogonen- density drops in ix, 100 setae on xxv; in vii no dorsal sis has preclitellar genital markings. The former has a or ventral gaps, in xxv ZZ:YZ = 2, no ventral gap. Cli- more posterior intestinal origin, the latter a more an- tellum annular 1/2xiii, xiv–1/2xvii; genital markings terior typhlosolar origin and spermathecal ampullae broad midventral ix (1), x slightly wider than sperma- undifferentiated from the ducts. One individual from thecal pore spacing; midventral round white area xv PTAGS055 had large numbers of small yellow nema- (1) triangular pad xvi, paired presetal in line with male todes under the peritoneum on the inner body wall sur- pores xix–xxii, or in less well developed specimens face from xii and posteriorly. midventral epidermal thickenings on xxii–xxiii (Fig-

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 10

Pleionogaster castilloi n. sp. midventral vessel on ventral esophageal wall, entering esophageal wall xviii. (Fig. 2I, J) Nephridia present as peptonephridia on anterior faces Etymology. Named after Augusto Castillo, one of septa 4/5/6, micronephridia preseptal clustered around the PTAGS logistics coordinators, who discovered un- commissural vessels vi–ix, on body wall thereafter; known reserves of strength climbing the crater wall of from xix 6 micronephridia per segment, 2 meganephri- Mt. Malinao. dia per segment from xix posteriorly, these attached to Type material. Holotype (NMA 004143): adult, tubules adherent to either side of dorsal vessel. PTAGS 055, Albay Province, near Tiwi, montane for- Ovaries and funnels free in xiii, spermathecae paired est on north ridge of Mt. Malinao, 13° 25.98’ N, 123° in viii, ix without nephridia on ducts; each spermatheca 37.63’ E, 850m asl, 10 May 2001, leg. S.W. James & A. with sagittate ampulla thinner-walled than duct; simp- Castillo. Paratype (KUNHM 002191): adult; collecting le club-shaped diverticulum joins duct near body wall, data as for holotype. slightly shorter than spermathecal duct (Figure 2J). Other material. KUNHM 002192: 3 adults, PTAGS Male sexual system holandric, testes and funnels en- 056, Albay Province, Barangay Jarod, upper mon- closed in annular sacs in x, xi, these sacs encompass tane forest on south ridge of Mt. Malinao, 13° 23.96’ hearts, seminal vesicles; sacs formed of membranes N, 123° 37.16’ E, 1030m asl, 11 May 2001, leg. S.W. connecting septa 9/10 and 10/11, 10/11 and 11/12; se- James and A. Castillo. minal vesicles xi, xii small, acinous; vasa deferentia Description. Unpigmented, body 93–113 mm x slender, non-muscular, adherent to ental 2/3 or more of 2.7–3.2 mm (vii), 2.6–2.9 mm (xv), 3.0–3.7 mm (xxv); prostatic duct, then fuse with duct; patch of microneph- 220–234 segments, most specimens amputees; body ridia surrounding duct-body wall contact; each prostate cylindrical in cross-section; segments x–xiii biannulate, racemose rounded mass, occupying xviii; with muscu- anterior half of postclitellar segments triannulate. First lar duct entering small muscular bulge at body wall; dorsal pore 11/12, 12/13; spermathecal pores paired copulatory bursae lacking. in 7/8, 8/9, 0.17 circumference apart, surrounded by Remarks. This species is characterized by six micro- thickened lips; female pores paired in xiv, male pore nephridia per segment, at the low end of the range, and openings crescentic, paired in xviii on porophores tilt- relatively many intestinal gizzards, the number ranging ed posteriorly, slightly depressed, 0.17 circumference from 5 to 7. The PTAGS 055 specimens from the north apart, 6–8 setae between male pores. Setae regularly ridge of Mt. Malinao all had 5 gizzards and the intesti- distributed around segmental equators; estimated at nal transition at 45/46, rather than 6 or 7 gizzards and 160–166 setae on vii, 70–80 setae on xxv; no dorsal or the intestinal transition at 47/48 as seen in the south ventral gaps. Clitellum annular 1/3xiii–1/2xvii; genital ridge material (PTAGS 056). I have chosen to include markings broad midventral 17/18, 18/19, 19/20; long these in one species based on the common number of shallow indentations in raised areas, somewhat like micronephridia and the similarity in male field genital the fusion of paired indented genital markings; mid- marking pattern. Distinction between P. castilloi and P. ventral epidermal thickenings on xxi–xxii (Figure 2I). malinaoensis has been discussed under the latter spe- Nephridiopores visible as gaps in setal rings and longi- cies. The next most similar species is P. sorsogonensis, tudinal musculature of postclitellar segments, 6 pores from which P. castilloi can be distinguished by the lack per segment in regular rows. of preclitellar and paired postclitellar genital markings, Septa 5/6–8/9 thick, muscular, 9/10 thinner, remain- the more posterior intestinal constriction, and a greater der membranous. Weak gizzard in viii with typical iri- number of setae (Table 2). descent outer wall but flaccid, esophagus valvular xix, Pleionogaster nillosae n. sp. intestinal origin xx, no caeca; thick intestinal gizzards xxv–xxix, xxv–xxxi, xxvi–xxx, xxvi–xxx, xxvi–xxxi; (Fig. 3A, B) typhlosole xlvii, xlviii–lxviii, lxx, lxvii, lxxv simple Etymology. Named after Portia Nillos, one of the fold, 0.16 lumen diameter. Intestine internal texture PTAGS logistics coordinators. changes from rugose to smooth xlvii, 45/46 (3), 47/48 Type material. Holotype (NMA 004144): preclitel- (2); intestinal wall vascularized xxxii–xlvii. late adult, PTAGS 122, Camarines Norte Province, Hearts x–xiii esophageal, commissural vessels v–ix Caramoan Peninsula, low-elevation forest on karst, lateral. Supra-esophageal vessel x–xviii, efferent pari- 13° 45.29’ N, 123° 53.81’ E, 346m asl, 22 May 2001, eto-esophageal vessels lacking, but vessels connecting leg. Y. Hong, M. Levi, P. Nillos. Paratype (KUNHM extraesophageal vessel to body wall present in each of 002193): juvenile; collecting data as for holotype. xiv–xvii, extra- esophageal vessels from vi to ix where Description. Unpigmented, body 250 mm (extend- they enter dorsal esophageal wall, in xiii fuse to single ed) x 5 mm (vii), 4.5 mm (xxv); 330 segments; body

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 11 cylindrical in cross-section; postclitellar segments tri- more anterior intestinal constriction, and different tes- annulate. First dorsal pore 12/13; spermathecal pores tes sacs (Table 2). The faint genital markings may be paired in 7/8, 8/9, 0.2 circumference apart; female pore due to immaturity. not seen, male pore openings crescentic, paired in xviii on small flat porophores, 0.18 circumference apart, no Pleionogaster caramoanensis n. sp. setae between male pores. Setae regularly distributed (Fig. 3C, D) around segmental equators; estimated at 314 setae on Etymology. Named for the Caramoan Peninsula on vii, 140 setae on xxv; no dorsal or ventral gaps. Genital the eastern side of Bicol. markings faint, paired presetal xvii, xix; slight thicken- Type material. Holotype (NMA 004145): adult, ing of epidermis over ventral surface of vii–ix (Figure PTAGS 123, Camarines Norte Province, Caramoan 3A). Nephridiopores visible as gaps in setal rings of Peninsula, low-elevation forest on karst, 13° 41.77’ N, postclitellar segments, 10 pores per segment in regular 123° 54.02’ E, 350m asl, 23 May 2001, leg. Y. Hong, rows. M. Levi, P. Nillos. Paratype (KUNHM 002194): adult; Septa 5/6–9/10 thick, muscular, 10/11, 11/12 thinner, collecting data as for holotype. remainder membranous. Weak gizzard in viii with typi- Other material. UPLBMNH Z-NS-0092: 2 adults, cal iridescent outer wall but flaccid, esophagus valvular PTAGS 121, Camarines Norte Province, Caramoan xix, intestinal origin xx, no caeca; six thick intestinal Peninsula, low-elevation forest on karst, 13° 44.40’ N, gizzards xxiv–xxix; typhlosole lacking. Intestinal tran- 123° 54.38’ E, 245m asl, 21 May 2001, leg. Y. Hong, sition obscured by poor preservation, in l–lv region. M. Levi, P. Nillos. KUNHM 002195: 1 adult, PTAGS Hearts xi–xiii esophageal, commissural vessels v–x 128, Camarines Norte Province, Caramoan Peninsula, lateral. Supra-esophageal vessel xi–xvii, efferent parie- low-elevation forest on karst 13° 46.09’ N, 123° 55.08’ to-esophageal vessels not seen due to damage; segmen- E, 31m asl, 24 May 2001, leg. Y. Hong, M. Levi, P. tal parietal vessel from body wall of xiv to extraeso- Nillos. phageal vessels xiv; extra-esophageal vessels not seen Description. Unpigmented, body 35–52 mm x anteriorly, fused mid-ventral below esophagus xiii–xx. 2–2.2 mm (vii), 2.1–2.4 mm (xv), 2.1–2.6 mm (xxv); Nephridia present as peptonephridia on anterior 123–206 segments; body cylindrical to slightly oval faces septa 4/5/6, micronephridia preseptal clustered in cross-section. First dorsal pore 12/13; spermathecal around commissural vessels vi–ix, on body wall the- pores paired in 7/8, 8/9, 0.13 circumference apart; fe- reafter; from xix 8–10 micronephridia per segment, 2 male pore single, male pore openings crescentic, paired meganephridia per segment from xix posteriorly, these in xviii on small flat porophores, 0.15 circumference attached to paired ureters adherent to either side of dor- apart, 6 setae between male pores; clitellum annular sal vessel. xiv–xvii. Setae regularly distributed around segmental Ovaries and funnels free in xiii, spermathecae paired equators; estimated 170–250 setae on vii, 110–160 se- in viii, ix without nephridia on ducts; each spermathe- tae on x, 82–100 setae on xxv; no dorsal gaps, ventral ca with elongate horn-shaped ampulla, muscular duct; gaps AA:AB = 2.5:1. Genital markings paired presetal, simple club-shaped diverticulum joins duct near body lateral to male pores xix, thickened white areas across wall, much shorter than ampulla (Figure 3B). Male se- ventral surface xix–xxi (Figure 3C). Nephridiopores xual system holandric, testes and funnels enclosed in visible as gaps in setal rings, longitudinal musculature annular sacs in x, xi, these sacs encompass hearts, se- of postclitellar segments, 4 pores per segment in regu- minal vesicles; sacs formed of membranes connecting lar rows. septa 9/10 and 10/11, 10/11 and 11/12; seminal vesicles Septa 5/6–9/10 thick, muscular, 10/11 thinner, re- xi, xii slender arches; each prostate racemose hemis- mainder membranous. Weak gizzard in viii with typi- pherical mass occupying xviii; with muscular S-curved cal iridescent outer wall but flaccid, esophagus valvular duct; copulatory bursae lacking, slight glandular deve- xviii (4), xix (1), intestinal origin 1/2xix (1), xix (4), lopment posterior to prostatic duct unions with body no caeca; thick intestinal gizzards xxvii–xxix (1) or wall, suggestive of genital marking glands. xxvi–xxviii (4); typhlosole low fold xxxix, xl–lviii. In- Remarks. Better characterization of this large, un- testine vascularized xix–xxvi, constricted xxxviii (1), pigmented species was prevented by the poor state of xxxix (4). preservation and by immaturity of the limited material Hearts x–xiii esophageal, commissural vessels ix obtained. For the time being it can be distinguished by lateral; vii, viii divide into several small vessels, appa- its large size, comparable to P. bicolensis but lacking rently none reaching ventral vessel. Supra-esophageal pigmentation, having fewer micronephridia per seg- vessel x–xvi, extra-esophageal vessels form from se- ment, more setae per segment but none between the veral smaller vessel in iii, iv, branches dorsally to sup- male pores, more gizzards (6) more anteriorly placed, ra-esophageal vessel in ix, other branch along ventral

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 12 esophageal wall to connect with efferent parieto-eso- gitudinal musculature of postclitellar segments, 4 pores phageal vessels from body wall of xvi, xvii. per segment in regular rows. Nephridia present as peptonephridia on anterior Septa 5/6–9/10 thick, muscular, 10/11–12/13 thin- faces septa 4/5/6, micronephridia preseptal clustered ner, remainder membranous. Weak gizzard in viii with around commissural vessels vi–ix, on body wall the- typical iridescent outer wall but flaccid, esophagus reafter; from xix 4–6 micronephridia per segment, 2 valvular xviii, intestinal origin xix, no caeca; thick in- meganephridia per segment from xix posteriorly, these testinal gizzards xxv–xxix, gizzards occupy posterior attached to paired ureters adherent to either side of dor- half of each segment as usual but anterior half of gut sal vessel. wall xxv–xxix somewhat iridescent, also covered with Ovaries and funnels free in xiii, spermathecae paired dense segmental network of blood vessels connected to in viii, ix without nephridia on ducts; each spermathe- dorsal and ventral vessels; typhlosole low fold xl–xlvii, ca with blunt cylindrical ampulla, clearly differentiated one fourth lumen diameter. Intestine constricted 38/39, muscular duct; simple club-shaped diverticulum half or thereafter coated with brown chloragogen layer. more length of main spermathecal axis joins duct near Hearts x–xiii esophageal, commissural vessels vii–ix body wall via differentiated stalk, (Figure 3D). Male lateral; supra-esophageal vessel x–xiv, extra-esophage- sexual system holandric, testes and funnels enclosed in al vessels not traceable; paired large longitudinal ves- annular sacs in x, xi, these sacs encompass hearts, dor- sels mid-lateral on body wall from xviii posteriorly. sal vessel, seminal vesicles; sacs formed of membranes Nephridia present as peptonephridia on anterior face connecting septa 9/10 and 10/11, 10/11 and 11/12; se- septa 5/6, micronephridia preseptal clustered around minal vesicles xi, xii loosely acinous; each prostate ra- commissural vessels vi–ix, on body wall thereafter; cemose four-lobed occupying xviii; duct not muscular; from xix four micronephridia per segment, two clearly vas deferens join prostatic duct one third distance from stomate meganephridia per segment from xix posteri- gland to body wall; copulatory bursae lacking. orly, these attached to paired ureters adherent to either Remarks. Pleionogaster caramoanensis is a small- side of dorsal vessel. bodied species with only three intestinal gizzards and Ovaries and funnels free in xiii, spermathecae paired only four micronephridia per intestinal segment. The in viii, ix without nephridia on ducts; each spermatheca other species with low numbers of nephridia are P. sor- club-shaped ampulla, poorly differentiated duct; simple sogonensis and P. isarogensis; both have many fewer club-shaped diverticulum half or more length of main setae per segment, and more gizzards (Tables 1, 2). The spermathecal axis joins duct near body wall (Figure former has preclitellar genital markings, the latter only 3F). Male sexual system holandric, testes and funnels postclitellar midventral markings, whereas P. cara- enclosed in annular? or ventrally separated? sacs in x, moanensis has only postclitellar paired markings. xi, these sacs encompass hearts, dorsal vessel, seminal vesicles; sacs formed of membranes connecting sep- Pleionogaster sorsogonensis n. sp. ta 9/10 and 10/11, 10/11 and 11/12; seminal vesicles (Fig. 3E, F) xi, xii loosely acinous; each prostate racemose two to Etymology. Named after the province that includes three-lobed occupying xviii; duct slightly muscular; the type locality. vas deferens slender, non-muscular; copulatory bursae Type material. Holotype (NMA 004146): adult, lacking. PTAGS 051, Sorsogon Province, Bulusan National Remarks. Pleionogaster sorsogonensis appears to be Park, dipterocarp forest at Bulusan Lake, 12° 45.32’ N, related to P. caramoanensis, with which it shares the 124° 05.34’ E, 360m asl, 3 May 2001, leg. S.W. James, same body size, pigmentation, and number of micro- A. Castillo, K. James, P. James. nephridia (Table 2). Pleionogaster sorsogonensis has Description. Unpigmented, body 46 mm x 2.3 mm two more intestinal gizzards, fewer setae in the anterior (vii), 2.6 mm (xxv); 117 segments (amputee); body cy- segments, fewer setae between the male pores, differ- lindrical. First dorsal pore 13/14; spermathecal pores ent genital marking patterns on the male field and in the paired in 7/8, 8/9, 0.11 circumference apart; female spermathecal segments, and spermathecae whose ducts pore not seen, male pore openings crescentic, paired and ampullae are not greatly differentiated. in xviii on small porophores, 0.15 circumference apart, 2 setae between male pores; clitellum not developed. Pleionogaster nautsae n. sp. Setae regularly distributed around segmental equators; (Fig. 3G, H) estimated 120 setae on vii, 114 setae on x, 72 setae on Etymology. Named after Phyllis Nauts of Connecti- xxv; no dorsal, ventral gaps. Genital markings midven- cut, USA, as a gift from her husband. tral 10/11, 11/12, xvi, xx–xxii; paired xvii, xix (Figure Type material. Holotype (NMA 004147): adult, 3E). Nephridiopores visible as gaps in setal rings, lon- PTAGS 071, Catanduanes Province, lower riparian for-

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 13 est near Barangay San Miguel, Pangabinan, LMK039, these attached to paired ureters adherent to either side 13° 54.5’ N, 124° 11.0’ E, 212m asl, 23 May 2001, leg. of dorsal vessel. S.W. James, J. ffitch, A. Castillo. Paratypes (KUNHM Ovaries and funnels free in xiii, spermathecae paired 002196): 2 adults; collecting data as for holotype. in viii, ix without nephridia on ducts; each spermatheca Other material. UPLBMNH Z-NS-0093: 2 adults, club-shaped ampulla not differentiated from duct; short PTAGS 068, Catanduanes Province, low-elevation basally-attached diverticulum of similar shape (Figure forest near Barangay Summit, Buradan, 13° 43.60’ 3H). Male sexual system holandric, testes, funnels en- N, 124° 17.14’ E, 210m asl, 21 May 2001, leg. S.W. closed in annular sacs in x, xi, these sacs encompass James, P. James, J. James, K. James, J. ffitch, A. Cas- hearts, dorsal vessel, seminal vesicles; sacs formed of tillo. KUNHM 002197: 1 adult, PTAGS 070, Catan- membranes connecting septa 9/10,10/11; 10/11, 11/12; duanes Province, lower montane forest near Barangay seminal vesicles xi, xii, slender arcs with large dorsal San Miguel, Pangabinan, no GPS data, 305m asl, 23 block; prostates racemose occupying xviii; duct mus- May 2001, leg. S.W. James, J. ffitch, A. Castillo. cular; vas deferens slender,non-muscular, adheres to Description. Unpigmented, body 158–295 mm x prostatic duct from duct-gland junction but visible on 3.3–4.6 mm (vii), 3.1–4.0 mm (xv), 3.5–4.3 mm (xxv); duct surface over ental one-third to one-half of duct; 286–343 segments; body cylindrical. First dorsal pore copulatory bursae lacking. 12/13; spermathecal pores paired in 7/8, 8/9, 0.13 cir- Remarks. Compared to P. nillosae, the other spe- cumference apart deep in furrows; female pore single, cies with six intestinal gizzards in xxiv–xxix (see Table male pore openings crescentic, paired in xviii on small 2), P. nautsae has fewer setae and micronephridia per porophores, 0.12–0.15 circumference apart, 0–7 setae segment, more narrowly placed male and spermathe- between male pores; pore orientation rotated so that cal pores, a typhlosole, and little or no differentiation crescent concavity directed antero-laterally rather than of the spermathecal duct and ampulla. It is one of two straight toward anterior; clitellum xiv–1/2xvii, annular. species in Bicol with preclitellar midventral genital Setae regularly distributed around segmental equators; markings, the other being P. sorsogonensis which has estimated 170–264 setae on vii, 150–196 setae on x, half as many micronephridia, a more anterior intestinal 92–106 setae on xxv; asetal zones midventral in one constriction and paired post-clitellar genital markings. or more of vii–ix. Genital markings narrow transverse midventral extending to male pore lines presetal xvii, Discussion xix, latter with embedded paired marks, paired indented Among those species for which many individuals were markings 17/18, broad epidermal thickenings ventral available for study, relative homogeneity of somatic presetal, equatorial annuli of xx, xxi; ventral epidermal and sexual characters is the rule. This is in contrast to thickenings presetal ½ vii, viii to ½ ix, x (Figure 3G). the definition of P. horsti generated by synonymizing Nephridiopores visible as gaps in setal rings, longitu- several species under this name (Easton 1979). Even dinal musculature of postclitellar segments, 8 pores per so, the species described here would fall well outside segment in regular rows. that wide net. Septa 5/6–8/9 thick, muscular, 9/10/11 thinner, re- In the course of this study, several characters not mainder membranous. Weak gizzard in viii with typi- generally recorded in previous work proved useful in cal iridescent outer wall, esophagus valvular xix or xx, distinguishing species. In the post-giceriate intestine intestinal origin xx or xxi, no caeca; intestine slightly there is always a constriction, either side of which both vascularized xxi–xxiv, thick intestinal gizzards xxiv– internal and external intestinal surfaces differ. The in- xxix; typhlosole simple fold from liii, liv; intestine ternal surface typically changes from rough and corru- constricted 50/51 or 51/52. gated anterior of the constriction to smooth posterior Hearts x–xiii esophageal, commissural vessels of it. The external intestinal surface is more densely vii–ix lateral; supra-esophageal vessel xi–xvii, extra- covered with tan or brown chloragogen posterior of the esophageal with branch from body wall of xiv, efferent constriction. In addition, the typhlosole (if present) al- posterior latero-parietal vessels travel up 15/16 to ex- ways begins after the constriction, whereas among the tra-esophageal vessel in xv, these connected to paired caecate genera of the Pheretima complex the typhlosole longitudinal vessels on body wall xviii–xl; not always (if present) begins just after the caeca (range xxii–xx- visible past xxx. vii) and thus many segments anterior to the typhloso- Nephridia present as peptonephridia on anterior les of Pleionogaster species. No other known member faces septa 4/5/6, micronephridia preseptal clustered of the Pheretima complex of genera (Sims and Easton around commissural vessels vi–ix, on body wall there- 1972; Easton 1979) has these intestinal features, or the after; from xix 8 micronephridia per segment, two sto- intestinal gizzards of Pleionogaster. mate meganephridia per segment from xix posteriorly,

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 14

Along the body wall in the anterior intestinal seg- te from and visible on the surface of the prostatic duct ments there is generally a longitudinal vessel on each over the ental half or more of the duct, before it mer- side, extending from the region of segments xv–xviii ges and dives in to unite with the prostatic duct lumen. back for 20–30 or even more segments. Sometimes this In the other genera, such as Pheretima and Amynthas, is not visible, probably due to lack of blood at fixati- the vas deferens lumen joins the prostatic duct near the on. Frequently this long vessel is clearly connected to branching point of the prostatic duct as it receives the a posterior latero-parietal vessel, which usually brings ductlets of the glandular lobes. blood from the clitellar body wall to the extra-esopha- Pleionogaster is so far known only from the Philip- geal vessel (s) located on the ventral side of the eso- pines, and no closely similar genera have been disco- phagus. More rarely, this same vessel is seen to also vered in other parts of SE Asia or the Australian regi- connect to the prostate gland circulation. Among the on, including New Guinea. How, and whence, it or its Pheretima group of genera, I have seen this longitudi- ancestor arrived on the Philippines and spread through- nal vessel on the body wall of the intestinal segments out the major islands without ending up anywhere else in Pleionogaster only. Gates (1972) reports a similar remains a mystery. vessel in Lampito, and I have seen a similarly placed Even though the collecting teams made prodigious vessel in a Honduran Ramiellona (James, unpublished efforts at each site visited, only a few species were col- data). lected from more than one area. Pleionogaster bico- All Pleionogaster possess an arrangement of nephri- lensis seems to be widely distributed across the Bicol dia unique within the perichaetine Megascolecidae. region, except for the extreme south where it was not Their micronephridia are arranged in regular rows with found on Mt. Bulusan. Pleionogaster caramoanensis is externally visible pores in the intestinal segments, and abundant and widespread on the Caramoan Peninsula. in clusters along the anterior septal faces and commis- This low-elevation limestone karst area was unsuitab- sural vessels in the head segments. The nephropores in- ly dry at the time of our visit, thus we have probab- terrupt the setal rings and longitudinal musculature, and ly not found all the species present at the Caramoan so are easily seen. The number of micronephridia per collection sites. Pleionogaster isarogensis was found segment appears to be relatively constant within a spe- at many collecting stations spanning a wide range of cies, only P. tiwiensis varying by more than a pair, and elevations within primary forest on Mt. Isarog, but not varies among species (range 4–14). While it is general- at any other location. Therefore, like most of the spe- ly true that larger species have more micronephridia per cies described here, it is probably endemic to its own segment, there are exceptions, notably P. bulusanensis particular mountain. It is worth recalling here that even with 14 though not being particularly large-bodied. All within the Mt. Malinao massif there is geographical species have a pair of stomate meganephridia in each variation of intestinal features in P. castilloi. The ex- intestinal segment, connected via tubules to ureters pa- tensive deforestation of the Philippines renders impos- rallel to either side of the dorsal vessel. sible any educated guesses about the original ranges The testes sacs of Pleionogaster are often different of Bicol’s native earthworm species. It is possible that from other perichaetine megascolecids in that some are some survive in scattered spots of older secondary fo- composed of membranes joining the septa enclosing rest or other areas with low disturbance frequency, but the testicular segments. In most other Pheretima group due to time and permit constraints we focused our ef- genera, and in the remaining Pleionogaster, the sacs do forts on easily defined locations where primary forest not enclose all the segmental contents, and usually only remains. the testes and funnels. The Pleionogaster sacs are most often annular, but in some cases they are U-shaped, Acknowledgements and open dorsally; in others the U is open ventrally, in This research was supported by the United States Nati- which case I have described them as horseshoe-shaped. onal Science Foundation through grant DEB-0072764 Annular sacs also occur in Philippine Pithemera and to the author and Maharishi University of Manage- Polypheretima (James, unpublished data) but in these ment. John Stimson prepared the illustrations. Hendon genera the sacs are never attached to both neighboring Chubb made a contribution to the author’s research septa. budget on behalf of his wife Phyllis Nauts. Thanks are Upon consideration of these apparent synapomor- due to the Philippine Department of Environment and phies Pleionogaster has little in common with the ge- Natural Resources, particularly to the Protected Areas nera of the Pheretima complex, other than being peri- and Wildlife Bureau staff who issued our permits, and chaetine and having the same male terminalia. Even the numerous DENR provincial offices and their emplo- latter show some variation from the common plan, as yees who worked with us in the field or simply pro- Pleionogaster have a vas deferens that remains separa- vided good information on access points and contacts

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 15 for the collecting sites. The National Power Corpora- Katharine James and David James provided assistance tion (NAPOCOR) provided access to the Mt. Malinao in the field. Finally, we thank the people of Barangay area within their geothermal development zone. Hong Summit, Catanduanes, for opening their homes to us Yong, Augusto Castillo, Portia Nillos, Matthew Levi, during our stay there. Jana ffitch, Dorothy Franke, Joy James, Pearl James,

References Beddard, F.E., 1895. A Monograph of the Order of Oligo- Jamieson, B.G.M., 1971. A review of the megascoleco- chaeta. Clarendon Press, Oxford, UK. id earthworm genera (Oligochaeta) of Australia. Part Easton, E.G., 1979. A revision of the ‘acaecate’ earthworms I—Reclassification and checklist of the megasolecoid of the Pheretima group (Megascolecidae: Oligochaeta): genera of the world. Proc. R. Soc. Qld. 82, 75–86. Archipheretima, Metapheretima, Planapheretima, Jamieson, B.G.M., 2000. Native Earthworms of Australia. Pleionogaster and Polypheretima. Bull. Brit. Mus. PDF document on CD-ROM. Science Publishers, Inc., Nat. Hist. (Zool.) 35, 1–128. Enfield, New Hampshire, USA. Gates, G.E., 1943. On some American and oriental Michaelsen, W., 1892. Terricolen der Berliner zoologischen earthworms part II. Family Megascolecidae. Ohio J. Sci. Sammlung, II. Arch. Naturg. 59, 209–261. 43, 99–116. Michaelsen, W., 1896. Oligochäten Kükenthal—Ergebnisse Gates, G.E., 1972. Burmese earthworms. An introduction einer zoologischen Forschungsreise in den Molukken to the systematics and biology of megadrile oligochaetes und in Borneo. Abh. Senckenb. Ges. 23, 192–243. with special reference to Southeast Asia. Trans. Am. Sims, R.W., Easton, E.G., 1972. A numerical revision of Phil. Soc. 62, 1–326. the earthworm genus Pheretima auct. (Megascolecidae: Heaney, L.R., 1985. Zoogeographic evidence for midd- Oligochaeta) with the recognition of new genera and le and late Pleistocene land bridges to the Philippine an appendix on the earthworms collected by the Royal islands. Mod. Quat. Res. SE Asia 9, 127–143. Society North Borneo Expedition. Biol. J. Linn. Soc. 4, Heaney, L.R., 1993. Biodiversity patterns and the conser- 169–268. vation of mammals in the Philippines. Asia Life Sci. 2, Stephenson, J., 1930. The Oligochaeta. Clarendon Press, 261–274. Oxford, UK. James, S.W., 2004. New species of Amynthas, Pheretima Stephenson, J., 1933. Oligochaeta from Australia, North and Pleionogaster (Clitellata: Megascolecidae) of the Carolina, and other parts of the world. Proc. Zool. Soc. Mt. Kitanglad Range, Bukidnon, Mindanao Island, Phil- Lond. 1932, 899–941. ippines. Raffles Bull. Zool. 52, 289–313.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 16

tiwiensis albayensis bicolensis bulusan- hongi ffitchae viracensis isarogensis ensis

Pigmentation none brown brown none pink brown brown none

Setae vii, xxv 210, 114 148, 85 130–220, 200, 120 176, 104 220, 160 200, 140 180, 76 140

Spermathecal pore 0.08 0.20 0.17 0.15 0.18 0.18 0.13 0.10 spacing

Male pore spacing 0.12 0.18 0.17 0.17 0.18 0.16 0.16 0.11

Setae betw. male 5, 6 12 8–10 20 10–12 8 10 4–8 pores

Midventral genital yes yes none none none none yes yes marks

Paired genital yes yes yes yes yes yes yes none marks

Nephridia/seg. 6–10 12 12 14 12 12 10 6

Intestinal orgin xix xx xix or xx xx xx xix xix xx

Typhlosolar origin xlvii xlvii none none xlvi l lii xli

Testes sacs annular annular open ventral annular annular annular annular annular x, U- shaped xi

Spermath. duct no no yes no no no yes yes differentiated

Latero-parietal xiv–xvii xiv–xvii xiv, xv xiv–xvi xiv–xvii xiv–xvi xiv, xv xv vessels

Table 1: Pleionogaster species with four intestinal gizzards in xxvii–xxx.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 17 Table 2. Pleionogaster species with three, five, or six intestinal gizzards.

malinaoensis castilloi nillosae caramoanensis sorsogonensis nautsae

Pigmentation none none none none none none Setae vii, xxv 160, 100 160, 80 314, 140 170–250, 120, 72 170–260, 110–160 100 Spermathecal pore 0.10 0.17 0.20 0.13 0.11 0.13 spacing Male pore spacing 0.09 0.17 0.18 0.15 0.15 0.13 Setae betw. male 2–4 6–8 0 6 2 0–7 pores Midventral genital yes yes ? none yes yes marks Paired genital marks yes none yes yes yes none Nephridia/seg. 10–12 6 10 4 4 8 Intestinal orgin xix xx xx xix xix xx, xi Typhlosolar origin xlv xlv or none xl xl liii xlviii Gizzards 5 5–7 6 3 5 6 Testes sacs annular annular annular annular annular annular Spermath. duct yes yes yes yes no no differentiated Latero-parietal xiv–xvii xiv–xvii xiv, ? xvi, xvii ? xv vessels

Table 2: Pleionogaster species with three, five, or six intestinal gizzards.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 18

A C E F 1 mm 3 B sp m

D m sp

1 sp m 5 5 m m m m m 1 0 m m xviii xviii

xviii

G I

H sp J sp 1 2 m 5 m m m 5 m m m m

xviii xviii

Fig. 1: A, B. Pleionogaster tiwiensis sp.n.; (A) ventral view, (B) spermatheca. C, D. Pleionogaster albayensis sp.n.; (C) ventral view, (D) spermatheca. E, F. Pleionogaster bicolensis sp.n.; (E) ventral view, (F) spermatheca. G, H. Pleiono- gaster bulusanensis sp.n.; (G) ventral view, (H) spermatheca. I, J. Pleionogaster hongi sp.n.; (I) ventral view, (J) sper- matheca. Abbreviation: sp=spermathecal pores.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 19

A C E

B F sp sp 2 sp 2 m m m m 1 0 5 m m m m 2 m D 5 m m m

xviii xviii

xviii

G I 1 mm sp

J H sp 1 m 5 m m 5 m m m

xviii

xviii

Fig. 2: A, B. Pleionogaster ffitchae sp.n.; (A) ventral view,. (B) spermatheca. C, D. Pleionogaster viracensis sp.n.; (C) ventral view,. (D) spermatheca. E, F. Pleionogaster isarogensis sp.n.; (E) ventral view,. (F) spermatheca. G, H. Pleio- nogaster malinaoensis sp.n.; (G) ventral view,. (H) spermatheca. I, J. Pleionogaster castilloi sp.n.; (I) ventral view,. (J) spermatheca. Abbreviation: sp=spermathecal pores.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006) James: The earthworm genus Pleionogaster (Clitellata: Megascolecidae) in S Luzon, Philippines 20

C A

D sp B sp 5 1 m 1 m 0 m 3 m m m m m

xviii

xviii G

E H sp 3 m m F 5 m 1 sp m m m 5 m m

xviii xviii

Fig. 3: A, B. Pleionogaster nillosae sp.n.; (A) ventral view,. (B) spermatheca. C, D. Pleionogaster caramoanensis sp.n.; (C) ventral view,. (D) spermatheca. E, F. Pleionogaster sorsogonensis sp.n.; (E) ventral view,. (F) spermatheca. G, H. Pleionogaster nautsae sp.n.; (G) ventral view,. (H) spermatheca. Abbreviation: sp=spermathecal pores.

Org. Divers. Evol. 6, Electr. Suppl. 8 (2006)