Neanthes sp. cf. Neanthes masalacensis (Grube, 1878)

Pamungkas, Joko & Glasby, Christopher J., 2015, Taxonomy of reproductive Nereididae (Annelida) in multispecies swarms at Ambon Island, Indonesia, ZooKeys 520, pp. 1-25 : 8-9

Neanthes sp. cf. Neanthes masalacensis (Grube, 1878) Fig. 5A, B

Nereis (Lycoris) masalacencis Grube, 1878: 75-76, pl. 5, fig. 4.

Material examined.

22 males (RCLA.Ann.038), 16 females (RCLA. Ann. 039), Suli, Ambon Island, Indonesia, 3°37'38.2"S, 128°18'25.0"E, coll. R. Alik, 18 March 2014 ; 5 males (RCLA.Ann.40), 1 female (RCLA. Ann. 41), Suli, Ambon Island, Indonesia, 3°37'38.2"S, 128°18'25.0"E, coll. R. Alik, 19 March 2014 ; 1 male (MZB.Pol.00171), 5 females (MZB. Pol. 00172), Suli, Ambon Island, Indonesia, 3°37'38.2"S, 128°18'25.0"E, coll. R. Alik, 18 March 2014 ; 3 males (NTM W25892 ) , 3 females (NTM W25891 ), Suli , Ambon Island, Indonesia, 3°37'38.2"S, 128°18'25.0"E, coll. R. Alik, 18 March 2014 ; Ambon Island, 4 females, 2 males (NTM W23805 ), collected D.S. Hoedt, 1866 (specimen extracted from a jar of many hundred worms in the collection of Naturalis, Leiden; Fig. 2) .

Size range.

Male: length (30-47 mm), width (2.5-3.0 mm). Female: length (30-50 mm), width (2.0-3.0 mm).

Diagnosis.

Neanthes species having uniform brown pigmentation on dorsal surface, apparently darker in male compared to female (Fig. 5A, B). Paragnaths conical arranged as follows: Areas I: 0; II: 10-13; III: 19-25; IV: 14-20; V: 0; VI: 1-2: VII-VII: 2-5 in line. Male and female epitokes both with natatory region extending to pygidium, but differ in number of pre-natatory chaetigers and number modified dorsal and ventral cirri. Male has pre-natatory region comprising 28-30 chaetigers; basally swollen dorsal cirri on chaetigers 1 to 7; basally swollen ventral cirri on chaetigers 1 to 6. Female has pre-natatory region comprising 32 chaetigers; basally swollen dorsal cirri on chaetigers 1 to 5; basally swollen ventral cirri on chaetigers 1 to 5. Also male has pygidial rosette and sub-distally swollen, scalloped dorsal cirri in anterior part of natatory region (dorsal cirri unmodified posteriorly), lacking in female. Female with brown pygidium.

Remarks.

The present material bears a general resemblance to Grube's species, which was described from Masalac, Philippines, in terms of pigmentation pattern and paragnath arrangement and counts. Our specimens differed in lacking paragnaths in Area I (Grube illustrates 2 paragnaths) and in the relatively longer dorsal cirri (up to 3 times length of parapodia in anterior chaetigers), whereas in Grube's specimens the dorsal cirri appear to be slightly longer than the parapodia, but the angle of the illustration makes it difficult to ascertain how much longer. It probably represents a new species.

Hartman (1959) referred Neanthes masalacensis to Pseudonereis based on the comparisons of earlier workers (e.g., Fauvel, Gravier) with other species of Pseudonereis . However, examination of the holotype of Nereis (Lycoris) masalacensis by Hutchings and Glasby (1985), showed the absence of elongated dorsal notopodial lobes in posterior chaetigers, and the original figure by Grube (1868) showed the paragnaths in Area II to be conical shaped rather than p-bars (sensu Bakken). Both features strongly suggest that the species does not belong to Pseudonereis . Hutchings and Glasby (1985) consider it to be indeterminable unless other material from the type locality (Masalac, Philippines) can be examined (and the distinctive pigmentation pattern matched). With this new material, from the same general biogeographic region (Western Coral Triangle) that resembles closely the type description of Neanthes masalacensis , we suggest the species be considered a member of Neanthes , as listed in Pamungkas (2015).