Nyctimene cyclotis Andersen, 1910

Irwin, Nancy, 2017, A new Tube-nosed Fruit Bat from New Guinea, Nyctimene wrightae sp. nov., A Re-diagnosis of N. certans and N. cyclotis (Pteropodidae: Chiroptera), and a Review of their Conservation Status, Records of the Australian Museum 69 (2), pp. 73-100 : 78-81

Nyctimene cyclotis Andersen, 1910

Figs. 2–3 , 5 , 10–12

Type locality. Arfak Mtns., Manokwari Division., Prov. of Papua, Indonesia.

Holotype. ♂ adult skin and skull, NHMUK 1910.7 .16.9

Common name. Round-eared tube-nosed fruit bat.

Specimens examined. ♂ NHMUK 1987.520 , adult, whole body in spirit and skull ( Arfak Mtns , Manokwari Division, Papua Prov., Indonesia) .

Distribution. Arfak Moutains, Papua Prov., Indonesia.

Revised diagnosis. Nyctimene cyclotis differs from N. certans in having a relatively longer upper post-canine tooth row (P 1 -M 1), which is only slightly shorter than P 3 -P 3, compared to P 1 -M 1 being markedly shorter than P 3 -P 3 in N. certans ; and in having a shorter second digit, especially 2-MET and 2M- 2P.

Nyctimene cyclotis shares with N. certans the following combination of characteristics to the exclusion of all other species in the subfamily: the ears are short (as wide as long), round, thickened along the apex and often spotted with yellow or white usually on the edge; dense, long dorsal fur (10–16 mm), a grizzled grey-brown caused by at least 30% of the base of the hair shaft being dark brown and the tips being dark brown; and almost indistinguishable ill-defined, short, thin dorsal stripe, which extends from the rump to the mid back; the 5M-1P is longer relative to 5-MET; M 1 -M 1 is shorter than P 4 -P 4, a character also shared with N. wrightae sp. nov.; breadth of the first molars (upper and lower) is markedly narrower relative to the breadth of fourth premolars (upper and lower).

Remarks. Essentially Andersen’s original diagnosis stands ( Andersen, 1910). Nyctimene cyclotis ranges in FA from 54.18 mm to 56.01 mm, known currently from only two male specimens. Andersen (1912a) described P 4, M 1 and M 1 of both N. certans and N. cyclotis as being sub-circular in outline and immediately distinctive from all other species. However the cheek-teeth of N. cyclotis , especially P 4 and M 1, are rectangular in shape (larger in the mesial-distal axis than the lingual-buccal axis), a feature that distinguishes it from the similar N. certans , in which the cheek-teeth are squarer (broader) in dimensions ( Fig. 2 , Table 2). M 1 and M 2 of N. cyclotis are sub-circular in shape, a feature only shared with N. certans ( Andersen, 1912a) .

The holotype of N. cyclotis has both forearms broken and Andersen (1910) therefore described it as having FAs that were approximately 53 mm (I measured it as 54.18 mm). The only other specimen that I assign to N. cyclotis is a male (NHMUK 1987.520) also from the Arfak Mountains. This specimen is a larger adult male than the holotype. The specimen has long hairs, 10–14 mm (depending on where they are measured) that are tricoloured, dark at the base, pale grey in the middle and dark again at the tips. The fur colour of both specimens has bleached due to fixation. It is assumed the bat originally was mottled grey-brown in colour due to the dark section at the base being up to one third the length of the shaft, a much larger proportion than in other Nyctimene species except N. certans . The tip of the hair is also dark. The specimen is paler in the neck and browner on the head, with the venter a dull cream. The holotype skull is badly damaged ( Fig. 2d ). Much of the back of the skull is missing (e.g. the squamosal and occipital); the right zygomatic arch is broken and half of the right side of the brain case and most of the basicranial floor is missing. The upper canines have been glued back into the tooth row, but not quite in the correct plane; the upper right P 4 and M 1 and the left upper incisor are missing. The anterior end of the left M 1 is worn to such an extent that there is no enamel left on the lingual side ( Fig. 2 ). The lower mandible is broken between P 3 and P 2 on the right and M 2 is missing on the left.

The length of the 5M-1P and 2M-2P separates N. cyclotis from other medium-sized species from New Guinea. The 5M-1P digit is relatively long compared to the 5-MET, with a ratio (5-MET/5M-1P) <1.9 ( Fig. 3 ); 2M-2P however is short, less than 7.5 mm and markedly shorter than N. certans for equivalent FA length. A larger series, however, may show overlap in these traits between N. cyclotis , N. wrightae and N. certans .

The second specimen of N. cyclotis (NHMUK 1987.520) was caught in 1986 by Ian Craven of World Wildlife Foundation PNG program. His notes on the specimen label indicate that the yellow colour on the ears is paler than the spots of the wings and both fade to white on fixation.

Nothing is known of the natural history of N. cyclotis and all natural history accounts attributed to this species to date are in my opinion not of this species.

Figures

Figure 2. Holotype skull and mandible of Nyctimene cyclotis NHMUK 1910.7.16.9; (a) mandible, right side is broken and left M is missing; (b) ventral view of cranium, right P4 2

Figure 3. Plot of 5-Metacarpal divided by the 1st phalanx of the 5 digit, verses 2nd phalanx of the 2nd digit, indicating separation of Nyctimene certans and N. cyclotis using 3 simple wing measurements for 255 specimens. Nyctimene certans (squares, n = 35), N. a. papuanus (circles, n = 128), N. wrightae sp. nov. (triangles, n = 90) and N. cyclotis (diamonds, n = 2). Holotype specimens are indicated for each species by an asterisk. Full or closed symbols indicate individuals identified genetically (n = 77), open symbols are those identified morphologically (n = 179).

Figure 5. Dorsal and ventral photographs of the holotypes of Nyctimene certans and N. cyclotis. (a, b) Holotype of N. certans NHMUK 1911.11.29.1; photographs courtesyof HarryTaylor (NHMUK).(c, d) Holotype ofN.cyclotis NHMUK 1910.7.16.9; photographs courtesy of Jeff Streicher (NHMUK). The ears are short and rounded in N. certans and N. cyclotis. Both FA’s of N. cyclotis are clearly broken. The dorsal stripe is difficult to distinguish in the base of the dorsal in N. certans and N. cyclotis. Overall there is a grizzled grey-brown appearance in the fur in the dorsal of N. certans and N. cyclotis, compared to a more even brown colour in N. wrightae sp. nov. and N. a. papuanus (see Fig. 6).

Figure 10. Plot of breadth against M1 breadth for Nyctimene a. papuanus (circles,n =58) N.certans (squares,n = 27), N.wrightae sp. nov. (triangles, n = 11) and N. cyclotis (diamond, n = 2). Filled symbols are genetically identified. Holotypes of each species indicated by star symbols. Smaller outliers of N. certans are old individuals with smaller teeth due to extensive tooth wear.Outliers of N. wrightae sp. nov. with larger teeth than their conspecifics are young individuals with little tooth wear.