Anisochaeta kiwi mihi, Blakemore, 2013

Blakemore, Robert J., 2012, On Schmarda’s lost earthworm and some newly found New Zealand species (Oligochaeta: Megadrilacea: Lumbricidae, Acanthodrilidae, Octochaetidae, & Megascolecidae s. stricto), Journal of Species Research 1 (2), pp. 105-132 : 114-115

Anisochaeta kiwi mihi sub-sp. nov.

[ Fig. 8 ]

Material Examined. Holotype ( AMNZ 5260 ), a single complete specimen, dissected, plus paratypes, P1-20 ( AMNZ 5261 ) comprising 20 specimens, several posterior amputees, of various life stages; (one was abnormal with marking 17/18 lhs but spermathecal pores in 6/7/ 8/9 and spiraling segments around 14). From Golden Springs Holiday Park ( GPS E2798840 .N6298535 300 m) at Mihi-Reporoa in Broadlands district central North Island near Taupo (38̊37′1′′S.176̊2′36′′E), beside pools of tepid creek (33̊C) feeding from local Golden Springs source that flows into the Waikato River via the Waiotapu Stream ; the soil was slightly black and sulphurous (low pH?) and the garden included exotic plants such as bamboo ( Pseudosasa japonica ?) as well as native trees (details: http://www.waikatoregion.govt.nz/PageFiles/20544/ 1.10Reporoa.pdf). Collector RJB, 11 th Sept., 2011.

Etymology. Mihi after district location of the sub-species with “mihi” meaning “to greet”.

Diagnosis. Anisochaeta as for A. kiwi kiwi but with dorsal pores from 4/5 and markings typically paired in 18/19, and rarely (in only one specimen with a rhs analogue) in 17/18, i.e., not found in 17 or 19 as typically seen in A. kiwi kiwi , or markings completely absent. mtDNA COI barcodes in Appendix I help define this sub-species.

Behaviour. Rapid escape response with autotomy of tail, and ejection of yellow coelomic fluid through (anterior) dorsal pores-all typical prey defensive responses of a superficial, litter-dwelling species.

Length. Holotype (H) ( AMNZ 5260 ) 88 mm, paratypes 60-80 mm for complete specimens. Widths. ca. 1-1.5 mm. Body/segments. (H) 98; body narrows and flattens to tail end that is often missing through autotomy/predation.

Colour. A brick brown-red dorsum with iridescent sheen, with a darker mid-dorsal line; pale ventrally; clitella buff.

Prostomium. Open epilobous; ventrally cleft peristomia.

First dorsal pore. From 4/5.

Setae. Perichaetine with ca. 32 on segment 12.

Nephropores. Not found (meroic).

Clitellum. Annular, ½13-16.

Male pores. Superficial and small eye-shaped on low papillae insunk on 18 in setal b lines.

Female pores. Single mid-ventral on 14.

Spermathecal pores. 7/8 and 8/ 9 in line with setal interval b or bc; an abnormal A. k. mihi paratype 65 mm long with markings in 18/19 had an extra segment spiral at 14 and an additional spermathecal pore in 6/7 lhs as well as those in 7/8/9.

Genital markings. Markings are most often paired in or near 18/19 wider than male pores, or markings may be unilateral in 17/18 or 18/19, or absent (e.g. in one paratype 80 mm long); one A. k. mihi paratype 75 mm long had marking unilateral in 17/18 rhs and another pair anteriorly on 19 below male pores. Some variation is thus apparently permissible. No glands were found internally in position of these markings.

Septa. None especially thickened, 12/13/14 are slightly stronger but still translucent.

Blood vessels. Dorsal vessel single, connects to supraoesophageal in 9-½14.

Hearts. Commissurals in 7-8, hearts in 9-12 from supraoesophageal vessel.

Gizzard. Compact and muscular in 5 preceded by pharyngeal mass to segment 4.

Calciferous glands. Oesophagus only slightly dilated in 13; valvular in 15.

Intestine. Origin in 16; caeca absent; typhlosole not found.

Nephridia. Meroic, forests of tubules equatorially with large tufted peptonephridia anteriorly in 4.

Testis/seminal vesicles. Holandric, paired testis in 10 and 11 free but invested in mucus; seminal vesicles paired, racemose in 9 and larger in 12.

Ovaries. Large and conglomerated egg mass in 13 with funnels posteriorly; small pseudo-vesicles in 14 anteriorly may actually be elongate ovisacs.

Prostates and penial setae. Small, paired S-shaped tubuloracemose gland with short duct; penial setae not found.

Spermathecae. Two pairs in 8 and 9 with globular ampullae each with a medium, elongate diverticulum not especially dilated terminally, opening by its own duct into short main duct.

Gut contents. Dark organic matter from their rich soil/ litter habitats.

mtDNA results. BLASTn alignment shows A. kiwi mihi H vs. A. k. kiwi H Identities =647/652 (99%) with no gaps; unlike the 100% agreement of A. kiwi kiwi H and

P1 (and of A. macleayi S1 and S2).

Remarks. Acuity of COI gene appears to vary, at least for this genus, with fine intraspecific concordance, but wide interspecific gap (cf. A. macleayi differing by 86%). Despite variation apparent in genital markings, Anisochaeta kiwi kiwi typically has markings in 17 and A. kiwi mihi , which may have fewer markings overall, does not. Possibly it merits combination, but mtDNA data gives tenuous molecular support to the conclusion from slight differences observed in makings and other morphological features that they represent discrete but potentially or actually interbreeding populations (i.e., sub-species) in their original homeland (s). Transportation to NZ (in plant pots?) is assumed to be recent (ca. 150 yrs or less?), as for A. kiwi kiwi and it is interesting that no translocated populations are yet known intervening between Auckland and Taupo. Further survey is obviously required.

Figures

Fig. 8. Anisochaeta kiwi mihi Blakemore sub-sp. nov. Holotype (AMNZ 5260) from Golden Springs. Ventral aspect with dorsal view of epilobous prostomium, spermathecae, prostate and oesophageal gland in 13 in situ; plus tail end.[Boxed spermatheca (near enlargement of 8 rhs) is Anisochaeta laingii (Benham, 1903) from Lee (1959: fig. 305) for comparison].