Platynereis mahanga
| Notice: | This page is derived from the original publication listed below, whose author(s) should always be credited. Further contributors may edit and improve the content of this page and, consequently, need to be credited as well (see page history). Any assessment of factual correctness requires a careful review of the original article as well as of subsequent contributions.
If you are uncertain whether your planned contribution is correct or not, we suggest that you use the associated discussion page instead of editing the page directly. This page should be cited as follows (rationale):
Citation formats to copy and paste
BibTeX: @article{Read2007Zootaxa1558, RIS/ Endnote: TY - JOUR Wikipedia/ Citizendium: <ref name="Read2007Zootaxa1558">{{Citation |
Ordo: Phyllodocida
Familia: Nereididae
Genus: Platynereis
Name
Platynereis mahanga Read, Geoffrey B., 2007 – Wikispecies link – Pensoft Profile
- Platynereis mahanga Read, Geoffrey B., 2007, Zootaxa 1558: 11-14.
Description
Nereis (Platynereis) australis.— Augener 1923: 27 –39, Fig. 16, Carnley Harbour, etc, Auckland I; Perseverance Harbour, Campbell I.
Diagnosis
Diagnosis. Secondary-tooth-tipped homogomph falcigers in juveniles, with replacement ceasing when about 50 chaetigers developed; homogomph falcigers absent in adults. Male heteronereid 2 -part, 18 (17–18) prenatatory segments, pygidial papillae structure a 2 -part fan of 8 large papillae. Female heteronereid 3 -part, 24 (22–25) pre-natatory segments, eggs blue, first 5 dorsal cirri enlarged. Benthic atoke dark green anteriorly, without or trace brown pigment on thickened lobes, prostomium or proboscis ring. Segment 11 notopodial superior ligule less bluntly rounded than preceding segment.
Materials Examined
Heteronereid material examined. Holotype. Wellington, Karaka Bay,41 ° 18.34 ' S, 174 ° 49.9 ' E, stn Y 10207, 0 m, 27.vi. 1970: het. male, 40 mm, coll G. Read, night light & dip net (NIWA3363, H- 872). Paratypes. Banks Peninsula. Menzies Bay, 43 ° 38.4 ' S, 172 ° 57.6 ' E:- stn GAK 19580501, 0 m, 1.v. 1958: het. 1 male, 1 female. Lyttelton Harbour, 43 ° 36.6 ' S, 172 ° 42.6 ' E:- stn GAK 19580000, 0 m, 1.vi. 1958: het. 1 male, 1 female. Kaikoura Peninsula. Kaikoura, 42 ° 24 ' S, 173 ° 40.8 ' E, 0 m 19.viii. 1961 (UCANTK K079A): het. 6 male, 6 female. Otago Harbour. Quarantine Island, 45 ° 49.8 ' S, 170 ° 37.2 ' E:- stn GAK19530606, 1 m, 6.vi. 1953: het. 1 male, 1 female. Wellington Harbour. Greta Point (Evans Bay), 41 ° 18.6 ' S, 174 ° 48 ' E:- stn Y 10152, 0 m, 24.viii. 2003: het. 1 male, 1 female. Houghton Bay, 41 ° 20.4 ' S, 174 ° 46.8 ' E:- stn Z 3875, 0 m, 2.viii. 1964: het. 1 male, 1 female. Karaka Bay, 41 ° 18.34 ' S, 174 ° 49.9 ' E:- stn Y 10203, 0 m, 28.v. 1970: het. 32 male, 18 female; stn Y 10204, 0 m, 30.v. 1970: het. 15 male, 22 female; stn Y 10206, 0 m, 24.vi. 1970: het. 4 male; stn Y 10207, 0 m, 27.vi. 1970: het. 43 male, 19 female; stn Y 10208, 0 m, 27.vii. 1970: het. 6 male, 6 female; stn Y 10209, 0 m, 25.viii. 1970: het. 2 male, 5 female; stn Y 10227, 0 m, 9.xi. 1971: het. 1 female; stn Y 10235, 0 m, 4.vi. 1972: het. 1 female; stn Y 10236, 0 m, 7.vi. 1972: het. 2 male; stn Y 10289, 0 m, 8.ix. 1975: het. 1 male, 1 female. Kau Bay, 41 ° 16.8 ' S, 174 ° 49.2 ' E:- stn Y 10216, 0 m, 1.v. 1971: het. 1 male; stn Y 10218, 0 m, 29.v. 1971: het. 1 female; stn Y 10219, 0 m, 16.vi. 1971: het. 1 male, 1 female; stn Y 10222, 0 m, 15.vii. 1971: het. 1 male; stn Y 10274, 0 m, 7.v. 1975: het. 1 male. Mahanga Bay, 41 ° 17.4 ' S, 174 ° 49.8 ' E:- stn Y 10241, 0 m, 3.viii. 1972: het. 3 female; stn Y 10242, 0 m, 10.viii. 1972: het. 49 male, 46 female; stn Y 10246, 0 m, 11.ix. 1972: het. 1 female; stn Y 10264, 0 m, 30.iv. 1973: het. 4 male, 1 female; stn Y 10267, 0 m, 29.vi. 1973: het. 5 male, 4 female; stn Y 10268, 0 m, 27.vii. 1973: het. 13 male, 13 female; stn Y 10269, 0 m, 24.viii. 1973: het. 3 male, 1 female; stn Y 10275, 0 m, 3.ix. 1975: het. 2 female. Wellington, coast south. Island Bay, 41 ° 21.02 ' S, 174 ° 46.11 ' E:- stn Y 10278, 0 m, 18.viii. 1976: het. 5 male, 11 female; stn Y 10281, 0 m, 9.ix. 1977: het. 1 male; stn Y 10284, 0 m, 6.x. 1977: het. 1 male. Non-type other material examined.Wairarapa, coast south, Windy Point, 41 ° 24 ' S, 174 ° 58.8 ' E:- stn Y 10322, 0 m, 17.iv. 1976: 22 atoke. Wellington Harbour, Kaiwharawhara, 41 ° 15.6 ' S, 174 ° 47.4 ' E:- stn Y10324, 2 m, 23.iii. 1977: 5 atoke. Karaka Bay, 41 ° 18.34 ' S, 174 ° 49.9 ' E:- stn Y 10315, 0 m, 30.iv. 1975: 12 atoke; stn Y 10318, 0 m, 8.ix. 1975: 7 atoke. Scorching Bay, 41 ° 18 ' S, 174 ° 50 ' E:- stn Y 10297, 0 m, 24.vi. 1970: 36 atoke. Wellington, coast west, Plimmerton north, 41 ° 4.8 ' S, 174 ° 51 ' E:- stn Y 10320, 0 m, 11.xi. 1975: 3 atoke. Size and shape. Atoke length up to 170 mm for 140 segments. Male heteronereid pre-natatory region almost uniform in width, but eighteenth parapodium often smaller than those anterior to it, posterior body narrow and tapered. Wellington region specimens mean length 33 mm, range 21–57 mm (std dev. 8 mm, n 45). Female heteronereid body uniform in width, Wellington region specimen mean length 29 mm, range 18–64 mm (std dev. 9 mm, n 36).
Description
Atoke description. Head region, paragnaths and proboscis, and parapodia and chaetae as in P. australis except area III paragnaths better developed, maxillary ring not usually expanded in width anteriorly, segment 11 notopodial superior ligule transitional, slightly conical rather than bluntly rounded. Atoke live colouration. Anterior dorsal body behind head green pigmented, dark pigment on head less developed than in P. australis, proboscis pigment absent, brown pigment on chaetiger 5 to 11 parapodial lobes slight or absent. Posterior pigment as in P. australis. Male heteronereid description. A two-part heteronereid. Enlarged eyes dark red and head carried bent down when proboscis retracted. Pre-natatory region with 18 (17–18) segments. Variation in Wellington specimens rare with fewer than 10 % with 17 segments (Table 4). Anterior first 7 dorsal cirri, first 4 ventral cirri enlarged, without variation (Fig. 2 A). Chaetiger 8–18 parapodia unmodified; anterior parapodia as in P. australis. Natatory parapodia beginning from chaetiger 19 (18) with morphology as in P. australis males, except posteriorly natatory region narrow, tapering, heteronereid lamellae absent or small, with parapodia correspondingly altered in shape (Fig. 2 C). Only natatory chaetae present, identical to those of P. australis. Taper of posterior body accentuated as axes of posterior parapodia directed upwards, at up to 80 degrees from the horizontal, so that parapodial structures dorsal. Pygidial structure a horizontally orientated ‘fan’ with a total of eight papillae divided into two branches of four (Fig. 2 B). Gravid male in-life colouration as in P. australis, except also scattered dots of reddish surface pigment on dorsal anterior body. Holotype male as above, 40 mm for 110 segments, with 18 pre-natatory segments, proboscis everted, paragnaths typical, except lines somewhat thickened, segments 5–10 with glandular blunt anterior superior notopodial ligules, segment 11 ligule transitional, slightly conical.
Location Number of pre-natatory segments Mean Std.dev.n17 17+t 18 18+t Cook Strait9 1 75 1 17.9 0.32 86Kaikoura6 0 0 0 17.0-6 Female heteronereid description. Three-part heteronereid but development of posterior region variable. Head and eyes as in male. Pre-natatory region with 24 (22-25) segments with fewer than 5 % with 22, 27% with 23, 55% with 24, and 3 % with 25 (Table 5). Anterior first 5 dorsal cirri enlarged (Fig. 6 D, 50 % of specimens) although 6 enlarged dorsal cirri common (38 %) and one specimen with 7 (Table 6). Always 4 enlarged ventral cirri. Parapodia of chaetigers 6–24 (mean values) unmodified. Natatory parapodia as in P. australis females. Posterior region of 20 to 30 segments with almost unmodified parapodia, usually lacking chaetae, although occasionally with a few natatory chaetae, notochaetal spinigers, and very rarely neurochaetal falcigers. Pygidium as in atoke except lacking anal cirri. Eggs 170–190 µm in diameter. Gravid females in life colouration blue except at extreme anterior due to colour of eggs masking all other body colour (Fig. 6 D). Dorsal blood vessel as prominent as in males, spent females appearing similar in colouration to spent males.
Location Number of pre-natatory segments Mean Std.dev.n22 22t 23 23t 24 24t25Cook Strait3 1 17 5 35 1 2 23.62 1.19 64Kaikoura0 0 0 2 3 0 1- -6
Location Number of dorsal enlarged cirri Mean Std.dev.n5 5t 6 7Cook Strait20 4 15 1 5.4 0.53 40 Juvenile chaetation and colour. Homogomph notopodial falcigers developing in laboratory-reared individuals at about 10 -chaetiger stage, with morphology as in P. australis. No wild juveniles obtained. Falcigers present at chaetigers 7–11 th at 13 -chaetiger stage, at 10–15 th at 17 -chaetiger, 10–21 st at 25 -chaetiger, and intermittently remain from chaetiger 32 at 45 -chaetigers and onwards. Juvenile pigmentation pattern of dorsal white surface pigment on head, on pygidium, and along midline on either side of dorsal blood vessel, and large lateral dots of red pigment on anterior 8 to 9 segments (Fig. 5 B). White midline pigment semi-continuous anteriorly, posteriorly usually in more or less rectangular blocks. Pattern apparent until white head pigment gradually lost and red pigment spots becoming smaller when about 50 chaetigers developed. White middorsal pigment then taking on linked-chain pattern, and diffuse green anterior colouration of adult present. Region of anterior thickened ligules present. Reproduction. At Wellington P. mahanga sp. nov. swarming occurred over an extended autumn to spring period, late March to November inclusive, with the period of maximum abundance late autumn to late winter (May to late August). Spawning in the laboratory occurred as in P. australis, except that P. mahanga sp. nov. males did perform rapid swimming in tight circles before spawning, and pairs did not spawn as readily. Males normally spawned first, but on two occasions P. mahanga sp. nov. females in a bowl together spawned one after the other although the males in the bowl did not spawn at all. Habitat. Intertidal and subtidal on rocky ground under stones and in crevices. A detritus and secretion tube is formed.
Distribution
Distribution.New Zealand mainland islands, Auckland and Campbell Islands.
Etymology
Etymology. The epithet mahanga is a noun in apposition.
Discussion
Remarks. Platynereis mahanga sp. nov. differs markedly from P. australis in heteronereid morphology, particularly in the male pygidial structure, and as an atoke less definitively in colour pattern and minor morphological differences. P. mahanga sp. nov. heteronereids were not significantly different in length between sexes or in relation to P. k a u sp. nov. They were larger than P. karaka sp. nov. and smaller than P. australis. Females usually had 6 more pre-natatory segments than males. Although P. mahanga males usually had 9 fewer pre-natatory segments than P. australis males, the ratio of total length to anterior region length was not significantly different. The pronounced taper of male bodies associated with more dorsally directed, less modified posterior parapodia is a feature shared with P. k a u sp. nov., along with the fan-like pygidial papillae. Augener (1923) recorded male heteronereids of this species from Auckland and Campbell islands as Nereis (Platynereis) australis. One specimen was a completely metamorphosed heteronereid in which the 18 th parapodium was the last of the pre-natatory region. Augener also figured the characteristic pygidial structure ‘mit handförmigen Fortsätzen’ (Augener, 1923 pp. 28–29, fig. 16).
Taxon Treatment
- Read, Geoffrey B.; 2007: Taxonomy of sympatric New Zealand species of Platynereis, with description of three new species additional to P. australis (Schmarda) (Annelida: Polychaeta: Nereididae), Zootaxa 1558: 11-14. doi
This treatment was originally uploaded by Plazi, compare this treatment on Plazi. Unless this treatment has been substantially changed on Species-ID, Plazi requests to maintain a link back to the original repository.
