Paedophryne swiftorum, Eric N. Rittmeyer, Allen Allison, Michael C. Gründler, Derrick K. Thompson & Christopher C. Austin, 2012

Eric N. Rittmeyer, Allen Allison, Michael C. Gründler, Derrick K. Thompson & Christopher C. Austin, 2012, Ecological Guild Evolution and the Discovery of the World’s Smallest Vertebrate, PLoS ONE 7 (1), pp. 1-11 : 2-3

Paedophryne swiftorum , sp. nov.

(urn:lsid:zoobank.org:act: 6 F 724864 -05 A 5-4729 - AB 27-7093 A 64 F 90 F 2)

Etymology. The species epithet honors the Swift family, in recognition of their generous contributions that enabled the establishment of the Kamiali Biological Station, where the type series was collected.

Holotype. BPBM 31883 (field tag AA 19195), adult male, collected by A. Allison, M.C. Gründler, E.N. Rittmeyer, and D.K. Thompson at Kamiali Wildlife Management Area, 1.3 km N, 6.2 km W of Cape Dinga, Cliffside Camp , Morobe Province, Papua New Guinea, 0 7.255997 °S, 147.092879 °E, 500 m elevation, 14 July 2008 .

Paratypes. BPBM 31879 , same data as holotype, except collected 8 July 2008; BPBM 31880 , same data as holotype, except collected 10 July 2008; BPBM 31881 - 82, same data as holotype, except collected 11 July 2008; BPBM 31884 collected by M. Gründler at Kamiali Wildlife Management Area, Pinetree Camp, Morobe Province, Papua New Guinea, 0 7.257906 °S, 147.06335 °E, 950 m elevation, 12 July 2008 ; BPBM 31885 , same data as BPBM 31884 , except an unsexed juvenile collected on 13 July 2008 ; BPBM 31886 , same data as holotype, except collected 13 July 2008 .

Diagnosis. A minute microhylid ( SVL = 8.25–8.90 mm) of the genus Paedophryne based on the following combination of characters: eleutherognathine jaw, 7 presacral vertebrae, first digits of hand and foot reduced to single elements, prepollex and prehallux reduced to single elements ( Fig. 1). Legs moderately long ( TL / SVL = 0.427–0.471), snout short and broad ( EN / SV = 0.064–0.071; EN / IN = 0.579–0.623), and eyes relatively large ( EY / SVL = 0.139–0.149). Fingers lacking enlarged discs (3 F / SVL = 0.018–0.024), toes with slightly enlarged discs (4 T / SVL = 0.041–0.047). Digits un-webbed; first finger and first toe reduced to vestigial nubs, second and fourth fingers and second and fifth toes also markedly reduced. Dorsum dark brown with irregular tan to rusty brown blotches or a broad tan mid-dorsal stripe; chin and throat dark brown, abdomen lighter brown, occasionally mottled with tan. Detailed mensural characters and proportions provided in Table 1 and Table 2.

Paedophryne swiftorum is distinguished from P. oyatabu and P. kathismaphlox by its smaller size ( SVL = 10.1–10.9 mm in P. kathismaphlox, 11.3 mm in P. oyatabu), longer legs ( TL / SVL = 0.35–0.39 in P. kathismaphlox, 0.40 in P. oyatabu,), and larger eyes ( EY / SV = 0.12 in P. kathismaphlox, 0.13 in P. oyatabu). Paedophryne swiftorum is further distinguished from P. kathismaphlox by its broader head ( EN / IN = 0.78–0.80 in P. kathismaphlox). It is distinguished from P. amauensis by its larger size ( SVL = 7.0– 8.0 mm in P. amauensis ), shorter legs ( TL / SVL = 0.478–0.507 in P. amauensis ), and shorter, broader head ( EN / SV = 0.075–0.084; EN / IN = 0.667–0.765 in P. amauensis ). The call of P. swiftorum differs from that of P. amauensis by its lower dominant frequency (8400– 9400 Hz in P. amauensis ), and by consisting of a series of four double notes, rather than repeated single notes as in P. amauensis . The individual notes are otherwise similar to P. amauensis . The calls of other Paedophryne species are unknown.

Call. The calling ecology of Paedophryne swiftorum is similar to

that of P. amauensis – it is generally crepuscular; however, it calls

diurnally during particularly wet conditions. It does not call

nocturnally regardless of rainfall. The call generally consists of four

double notes ( Fig. 2; Table 4) delivered in a continuous series at

the rate of 0.66 calls/s. Each note is around 7 ms in duration and

the entire call lasts approximately 0.5 seconds. The interval

between notes is 40–50 ms within a double note series and 85–

100 ms between each double note series. The dominant frequency

averages 7300 Hz. Some individuals occasionally produce calls of only six notes, invariably consisting of double notes, and otherwise similar to eight-note calls. The acoustic characteristics of the call and the tendency of males to call continuously within a chorus produces an uncanny resemblance to stridulating orthopteran insects.

Tables

Table 1. Mensural characters of Paedophryne amauensis and P. swiftorum.

Catalogue No.	Species	Sex	SVL	TL	EY	EN	IN	SN	HW	HL	3F	4T
LSUMZ 95000*	P. amauensis	Male	7.50	3.80	1.05	0.60	0.80	0.85	2.85	2.15	0.25	0.30
LSUMZ 95001	P. amauensis	Male	7.00	3.55	0.95	0.55	0.75	0.65	2.75	1.90	0.20	0.25
LSUMZ 95002	P. amauensis	Male	7.85	3.75	1.00	0.60	0.80	0.95	2.75	2.25	0.20	0.30
LSUMZ 95003	P. amauensis	Male	8.00	3.90	1.20	0.60	0.85	0.75	2.90	2.30	0.25	0.40
LSUMZ 95004	P. amauensis	Male	8.00	3.95	1.10	0.60	0.90	0.95	2.90	2.20	0.25	0.30
LSUMZ 95005	P. amauensis	Male	7.70	3.80	1.00	0.65	0.85	0.95	2.90	2.10	0.20	0.30
LSUMZ 95006	P. amauensis	Male	7.85	3.80	1.10	0.60	0.85	0.85	2.75	2.25	0.20	0.30
BPBM 31880	P. swiftorum	Male	8.50	3.95	1.20	0.55	0.95	0.80	2.80	2.40	0.15	0.35
BPBM 31881	P. swiftorum	Male	8.90	3.80	1.25	0.60	0.95	0.85	2.90	2.50	0.20	0.40
BPBM 31882	P. swiftorum	Male	8.40	3.70	1.25	0.60	0.95	0.80	3.00	2.40	0.20	0.35
BPBM 31883*	P. swiftorum	Male	8.55	4.00	1.25	0.55	0.95	0.85	3.00	2.50	0.15	0.35
BPBM 31884	P. swiftorum	Male	8.25	3.85	1.15	0.55	0.90	0.80	2.90	2.35	0.20	0.35
BPBM 31885	P. swiftorum	Juvenile	4.45	1.75	0.75	0.25	0.50	0.50	1.75	1.40	0.20	0.20
BPBM 31886	P. swiftorum	Male	8.50	4.00	1.25	0.55	0.90	0.85	3.00	2.45	0.20	0.40