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Short Communications SALAMANDRA 44 1 54-58 Rheinbach, 20 February 2008 ISSN 0036-3375 Notes on reproduction in fi ve species of Emoia (Squamata: Scincidae) from Papua New Guinea Stephen R. Goldberg & Fred Kraus Abstract. Males of Emoia caeruleocauda, E. jakati, E. longicauda, E. obscura and E. pallidiceps from Pa- pua New Guinea exhibit extended periods of sperm formation. Emoia caeruleocauda, E. longicauda, E. obscura produced clutches of 2 eggs; E. jakati and E. pallidiceps produced clutches of -2 eggs. One E. ob- scura female contained corpora lutea from a previous clutch and concomitant yolk deposition, and two contained oviductal eggs and concomitant yolk deposition for subsequent clutches, indicating the pro- duction of multiple clutches under natural conditions. Estimates of minimum sizes for sexual maturity are given for each Emoia species. Key words. Scincidae, Emoia caeruleocauda, Emoia jakati, Emoia longicauda, Emoia obscura, Emoia pal- lidiceps, reproduction, Papua New Guinea. Th e skink genus Emoia consists of 72 spe- these species except for E. longicauda, which cies ranging from southeastern Asia to the has not been studied, produce clutches of two islands in the Central Pacifi c (Brown 99). eggs (Brown 99, McCoy 2006). Th e pur- Th e greatest diversity ofEmoia species occurs pose of this report is to present the fi rst his- on New Guinea and adjacent islands (Brown tological information on reproductive cycles 99). Ecological data are available for rela- for each of these species based on an exami- tively few of these species, probably refl ecting nation of gonadal material of specimens from the remoteness of most species from centers Papua New Guinea. Estimates of minimum of herpetological research activity. Nonethe- sizes at maturity are given for each species. less, most species investigated to date lay two Th e fi rst information on the reproductive bi- eggs and hatchling sizes have been reported ology of E. longicauda is presented. for several species (Greer 968, Brown 99, Emoia skinks from Milne Bay Province, Morrison 2003). Papua New Guinea were examined from Emoia caeruleocauda is known from Bor- the herpetology collection of the Bernice P. neo, Palau, Mariana Islands, Caroline Islands, Bishop Museum (BPBM), Honolulu, Hawaii. Marshall Islands, southern Philippines, Su- Skinks were collected from 2002 to 2004 as lawesi, Moluccas, New Guinea and associ- part of biodiversity surveys and were stud- ated island archipelagos, Solomon Islands, ied from a geographically constrained region Vanuatu and Fiji; Emoia jakati is known (Milne Bay Province) so as to minimize the from Palau, Caroline Islands, Marshall Is- potential for confounding geographic varia- lands, New Guinea and adjacent island archi- tion in the reproductive cycles (Appendix). pelagos, and Solomon Islands (Brown 99, Survey schedules disallowed comprehensive McCoy 2006). Emoia longicauda is known sampling throughout the year but were suf- from New Guinea, Cape York Peninsula in fi ciently spaced in time to allow some infer- Queensland, Australia, Admirality Islands ence of yearly reproductive patterns. Th e left and Mussau Island, north of New Ireland; testis and ovary were removed, processed by Emoia obscura and Emoia pallidiceps are re- standard histological techniques and stained stricted to New Guinea (Brown 99). All with Harris’ hematoxylin followed by eosin © 2008 Deutsche Gesellschaft für Herpetologie und Terrarienkunde e.V. (DGHT) http://www.salamandra-journal.com Short Communications counterstain (Presnell & Schreibman 2. SD, 0.56 SE, range = 4-48 mm; 25 males 997). Histology slides were deposited at with mean SVL = 4.6 mm ± 3.5 SD, 0.70 SE, BPBM. Maturity of males was recognized by range = 33-47 mm; 4 neonates with mean SVL their having spermiogenesis in progress, of = 26.0 mm ± 2.6 SD, .3 SE, range = 23-29 mm. females by their undergoing yolk deposition. All males were undergoing spermiogenesis: Clutch size of females was determined from January (5 males), August (4), September enlarging follicles or oviductal eggs. Lizard (6). Th e smallest reproductively active male snout-vent length (SVL) was measured using measured 33 mm SVL (BPBM 5934) and was a plastic millimeter rule to the nearest mil- taken September 2002. Reproductively ac- limeter. tive females were present in the three months Two stages were observed in the testicu- sampled (January, August and September) lar cycle: () recrudescence, in which there (Table ). Mean clutch size for 2 females was is a proliferation of cells in the germinal epi- .8 ± 0.39 SD, 0. SE, range: -2. Th e smallest thelium for the next period of spermiogen- reproductively active females with oviductal esis (sperm formation). Primary and second- eggs (BPBM 5935) and enlarged ovarian fol- ary spermatocytes are the predominant cells; licles (> 6 mm) (BPBM 5955) both measured some spermatids but no spermatozoa may be 4 mm SVL and were from September 2002. present; (2) spermiogenesis, in which sem- One neonate was from April (BPBM 9988), iniferous tubules are lined by spermatozoa one from August (BPBM 5922), two from and clusters of metamorphosing spermatids September (BPBM 5937, 5950). are present. Emoia longicauda: Th e sample (n = 24) Emoia caeruleocauda: Th e sample (n = 24) consisted of 4 females with mean SVL = 8. consisted of 4 females with mean SVL = 46.3 mm ± 5. SD, .3 SE, range = 69-87 mm; 9 mm ± 2. SD, 0.57 SE, range = 43-49 mm; 7 males with mean SVL = 86.4 mm ± 8.8 SD, 2.9 males with mean SVL = 49.0 mm ± 3.5 SD, .3 SE, range = 68-00 mm; neonate with SVL = SE, range = 44-54 mm; 3 neonates with mean 38 mm. All males were undergoing spermio- SVL = 24.0 mm ± 2.7 SD, .5 SE, range = 22- genesis: January (6 males), April () and May 27 mm. All males were undergoing spermio- (2). Th e smallest reproductively active male genesis except for one male obtained in Janu- measured 68 mm SVL (BPBM 680) and ary that was in late recrudescence. It meas- was taken January 2003. Reproductively ac- ured 44 mm SVL (BPBM 6730) and con- tive females were present in three of the four tained metamorphosing spermatids but no months sampled: January, February, and May sperm. Males undergoing spermiogenesis (Table ). Th e one April female was reproduc- were from: January (3 males); April (); Sep- tively inactive. Mean clutch size for 6 females tember (2). Th e smallest reproductively ac- was 2.0, 0.0 SD, 0.0. SE. Th e smallest repro- tive male (spermiogenesis in progress) meas- ductively active female measured 77 mm SVL ured 45 mm SVL (BPBM 9985) and was tak- (BPBM 6792) and was from January 2003. en April 2004. Reproductively active females Two females, 69 mm SVL (BPBM 6797) and were present in the three months sampled 72 mm SVL (BPBM 6804) were not repro- (January, April and September) (Table ). ductively active. One neonate (BPBM 20742) Mean clutch size for females was 2.0, 0.0 was from April. SD, 0.0. SE. Th e smallest reproductively ac- Emoia obscura: Th e sample (n = 57) con- tive females measured 43 mm SVL (BPBM sisted of 24 females with mean SVL = 5.6 998) from April 2004 and (BPBM 6722) mm ± 5.0 SD, .0 SE, range = 39-60 mm; 29 from January 2003. One neonate (BPBM males with mean SVL = 49.7 mm ± 6.6 SD, .2 6728) was from January, two (BPBM 9982, SE, range = 34-60 mm; 4 neonates with mean 9983) were from April. SVL = 27 mm ± .8 SD, 0.9 SE, range = 25-29 Emoia jakati: Th e sample (n = 43) consist- mm. All males were undergoing spermiogen- ed of 4 females with mean SVL = 44.3 mm ± esis: April (8 males), May (8) and September 55 Short Communications Tab. 1. Stages in ovarian cycle of fi ve species of Emoia skinks from Papua New Guinea. *Two E. obscura females with oviductal eggs also contained follicles undergoing yolk deposition. **Represents one E. obscura from September (not in the table) with corpora lutea from a previous clutch and yolk deposi- tion for a subsequent clutch. Number of speci- Quiescent Early yolk depo- Enlarged follicles Oviductal eggs mens sition > 3 mm Emoia caeruleocauda 4 January 9 0 7 April 3 0 2 0 September 2 0 0 Emoia jakati 4 January 4 0 2 August 0 0 0 September 9 4 3 Emoia longicauda 4 January 5 2 0 2 February 0 0 0 April 0 0 0 May 7 2 3 2 0 Emoia obscura 24 February 0 0 0 April 0 0 5 4* May 7 2 2 2 September** 5 0 0 2 2 October 0 0 0 Emoia pallidiceps 22 January 6 0 2 3 February 9 0 5 3 April 0 0 0 August 0 0 0 September 2 0 0 October 3 0 2 0 (3). Th e smallest reproductively active male Mean clutch size for 8 females was 2.0, 0.0. measured 34 mm SVL (BPBM 555) and was SD, 0.0 SE. Th e smallest reproductively ac- taken 22 April 2002. Reproductively active tive female measured 39 mm (BPBM 5974) females were present in the fi ve months sam- and was from September 2002. One neonate pled: February, April, May, September, and (BPBM 5526) was from April, one from May October (Table ). One female from Septem- (556), one from August (BPBM 5562) and ber (BPBM 5974) contained corpora lutea one from September (BPBM 5976). from a previous clutch and yolk deposition Emoia pallidiceps: Th e sample (n = 35) for a subsequent clutch, and two females consisted of 22 females with mean SVL = 5.3 from April (BPBM 5524, 5529) with oviduc- mm ± 5.0 SD, . SE, range = 43-60 mm; 2 tal eggs were also undergoing yolk deposition males with mean SVL = 49.0 mm ± 4.4 SD, for a subsequent clutch, indicating E.