New species and records of the earthworm genus Ramiellona (Annelida, Oligochaeta, Acanthodrilidae) from southern Mexico and Guatemala
Author
Fragoso, Carlos
Author
Rojas, Patricia
text
Zootaxa
2014
3753
6
549
572
journal article
46698
10.11646/zootaxa.3753.6.3
715c7010-c4b2-4910-b707-62a84ba9a6d0
1175-5326
224299
8DF3EFAA-F8CC-4D4C-A830-D07D76C2D1C0
Ramiellona tojolabala
sp. nov.
Figures 1
,
2
Localities and material.
Mexico
, Chiapas, National Park Lagunas de Montebello:
(1)
Type
locality: 3.5 km after the entrance to the park, towards Tziscao. In the forests at right hand of the entrance to “Lago de Montebello”,
100 m
away from the lake shore. Slightly disturbed pine-oak forest over a N-faced slope; within soil at
0–20 cm
depth.
16°06’16”N
,
91º42’13”W
,
1490 m
a.s.l.. 19J-23A-15CA (with 2, 9, and 4 posterior amputees, respectively),
11/19/ 1981
, C. Fragoso and P. Lavelle. 6J-4A-3CA,
11/27/1997
, C. Fragoso and J. Bueno.
(2)
2 km
after the entrance to the Park, towards Tziscao
300 m
by a rural road. Ecotone cloud forest - pine oak forest with abundant bromeliads, within soil at
0–20 cm
depth.
16°4’38”N
,
91°43’10”W
,
1540 m
a.s.l., 8J-1A,
11/27/1997
, C. Fragoso and J. Bueno.
(3)
km 6 on route to Tziscao,
4 km
after “Cinco lagos”. Well preserved cloud forest and adjacent recently cleared forest, within soil at
0–20 cm
depth.
16°7’2”N
,
91°40’8”W
,
1500 m
a.s.l., 2A-4CA,
11/28/1997
, C. Fragoso and J. Bueno.
Holotype
.
One clitellate adult collected
11/27/
1997
in locality
(1)
,
IEOL
4238.
Paratypes
.
Five clitellate adults collected in locality
(1)
,
11/19/1981
:
IEOL
2149, 2150, 2151, 2155, and in locality
(3)
,
IEOL
3336, dissected. Further 20 individuals, characterized only externally: localities
(1)
,
11/19/1981
:
IEOL
2154, 3360, 4229, 4230, 4231, 4232, 4233, 4234, 4235, 4236, 4237;
11/27/1997
:
IEOL
4219, 4220, 4239, 4243;
(2)
,
IEOL
3320;
(3)
,
IEOL
4240, 4241, 4242, 4243.
FIGURE 1.
Ramiellona tojolabala
sp. nov
.
A.
External ventral view of anterior region.
B.
Spermatheca from segment
9
, dorsal view.
C.
Transverse section (hand made dissection) from segment
9
, showing the esophagus and dorsal stalked calciferous glands. D = dorsal, V = Ventral. Holotype IEOL 4238. Scale 1 mm.
Description. External.
Length
50–120 mm
(mean=78.9 mm, n=19;
holotype
103 mm
); width (postclitellar) 1.6–2.5 mm (mean=2.11, n=23;
holotype
1.8 mm). Segments 128–239 (mean=189, n=14;
holotype
213). Pigment absent. Prostomium prolobous, invaginated in the majority of individuals. Peristomium with several longitudinal annulations; in several individuals these grooves also present in the second segment. Secondary furrows: one postsetal in
7
and
8
; in
9–13
one presetal and one postsetal; behind clitellum generally absent. Setae eight per segment, visible from segment
2
, closely paired in the anterior region and quincuaxial in the posterior region. Setal formula in anterior region (average, n=5) (
aa:ab:bc:cd:dd
):
10
: 2.9:1:7.3:0.6:34.9;
30
: 4:1:4.2:1.2:39.1. In all individuals the first seta that shifts is seta
c
, then seta
d
and finally seta
b
; setae
a
never move and thus row
A
is recognized throughout. The quincuaxial arrangement occurs always in the second half of the body, after segment 100 (average beginning after 65% of segments, range 55–80%, n=12). Spermathecal setae present in some individuals (
c
. 50%), on one or both sides of
6
and
7
(one ind.),
7
(14 ind.) or
7
and
8
(one ind.), sometimes surrounded by swellings (
Fig. 1
A). Spermathecal setae slightly curved, without ornamentation, measuring 0.73– 0.93 mm, apex slightly arrow-shaped (
Fig. 2
C,D). Penial setae very conspicuous, robust, paired (
a
and
b
) in
17
and
19
, semicircular (
Fig. 2
A); those of
17
always slightly smaller (length 0.93–1.12 mm, width 70 µm) than those of
19
(1.02–1.31 mm, 100 µm). Apex with a slight undulation, ending in an acute tip; ornamentation limited to undulation, consisting in several irregular rows of small, apex oriented thorns (
Fig. 2
B). Setae
a
and
b
of
18
visible.
FIGURE 2.
Ramiellona tojolabala
sp. nov
.
A.
Penial seta
a
of segment
19
(scale 200 µm). SEM photographs.
B.
Apex of penial seta
19
a
(scale 50 µm).
C.
Spermathecal seta
a
of segment
7
(scale
100
µm).
D.
Apex of spermathecal seta
7
a
(scale 20 µm). Paratype IEOL 2149.
Clitellum dark to light orange, dorsally in
13–19
(one ind.),
1/2
13
–19 (8 ind.),
14–19
(6 ind.) or
14
–1/2
20
(one ind.); ventrally in
13–19
(one ind.),
1/2
13
–19 (7 ind.),
14–19
(7 ind.) or
1/4
13
–1/4
20
(one ind.); saddle shaped in the region of the genital zone (
17–19
) and (in some individuals) in
15–16
, reaching setae
b
; in some individuals fused with swellings of segments
14–16
. Intersegmental furrows of clitellum recognizable in some individuals (
Fig. 1
A). Large dorsal pores present all along the body, first pore in 12/13 (n=20). Spermathecal pores paired in 7/8 and 8/9, very large, centered in
AB
(
Fig. 1
A), the posterior edge of each pore with iridescence. Due to their size, in some individuals the pores appear to be in segments
8
and
9
, but when looking inside the pore the duct is clearly in the respective intersegment. Female pores in
14
, presetal and slightly median to
a
, within an ovoidtriangular papilla extending in
BB
(
Fig. 1
A). Two pairs of prostatic pores in
17
and
19
just at the base of seta
b
, joined by square bracket-shaped seminal grooves, which run outside
B
(
Fig. 1
A). In some individuals the seminal groove is more bracket-like, whereas in others it curves slightly in
18
towards seta
b
. Male pores in 17/18, within the seminal groove, outside
B
; in fully clitellate individuals pores difficult to see. Genital marks unpaired (
Fig. 1
A) as mid-ventral, intersegmental papillae located in some intersegments of region 16/17–23/24; shape ovoidrectangular, extending into
AA
,
BB
or (more commonly) from outside
B
to outside
B
. Papillae in 20/21 and 21/22 mostly present (16 ind.).
Holotype
with papillae in 19/20–22/23. Papillae largest in 2nd or 3rd position, smallest generally in the last position. In some clitellate adults papillae of 17/18, 18/19 difficult to recognize, seeming more like swellings.
Internal.
Septa
5/6 and 12/13
very thin and membranous; 11/12 slightly muscular;
6/7–10/11
muscular; septa
6/7–10/11
funnel-shaped and imbricated, those of
8/9–10/11
joined by 4–8 dorsal and lateral connective tissue fibers. One large gizzard in
5,
extending up to
7–8
. Extramural calciferous glands present in
7–12
(n=6), as dorsolateral sacs that open into the esophagus through a medium-sized conduct (
Fig. 1
C); internally each sac with large, numerous lamellae with free margins. Size of sacs:
7
≤
8 ≥ 9
>
10
>
11
>
12.
Intestine begins in 14/15 or 15/16. Intestinal typhlosole starting in
15
or
16
, as a small fold increasing in size in
21
,
22
, lamina-shaped in
23
or
24
with free edge divided into three deep ridges (i.e. typhlosole trifid), continuing with same shape until abrupt end in
123
,
124
,
126
. In
24–28
with up to 13 lateral folds, straight or slightly oblique in posterior direction. Smaller dorsolateral typhlosoles covering 6–7 segments in the region of
21–28
, at both sides of main typhlosole. Intestinal caeca present as one or two paired dorsal pouches of the intestine in
21–24
.
Single dorsal vessel visible throughout. Supra-esophageal vessel visible in
8–12
. Lateral hearts in
7
,
8
,
9
and
10
; latero-esophageal hearts in
11
and
12
. Ventral vessel present. Extra parietal ventral vessels in each side of
13
,
14
,
15
and
16
, running outside male gonoduct joined in
13
to paired infra-esophageal vessels, which run anteriorly until
7
; vessels in
7
and
8
joined to lateral commissures before anastomosing with anterior septum and fusing with the ventral vessel. Paired clusters of tufted micronephridia along a longitudinal row in
2–4
; septal meronephridia observed in the anterior face of septa
7/8–12/13
(four, two on each side). Parietal, closed meronephridia from
14
backwards; in some individuals four on each side (eight per segment) from
28–39
; from
40
on only three nephridia observed on each side. Median ventral nephridium of last segments larger and with a small nephrostome into the preceding segment.
Holandric. Testes of
10
and
11
bushy and very large, joined to the male funnels by abundant coagulum and located mid-ventrally on the anterior septum. Male funnels iridescent and plicated, placed at both sides of the midventral line of the posterior septum; funnels of
11
larger than those of
10
. Male gonoducts double, running along body wall in
BC
of
13–17
, muscular in region
15–16,
entering body wall in 17/18 just below the muscular duct of the prostate, towards mid-ventral line. Two pairs of seminal vesicles in
9
and
12
, respectively fixed to septa
9/10 and 11/12
; the anterior pair slightly smaller and in some individuals flat; the posterior pair larger and acinous. Two pairs of tubular prostates of similar size in
17
and
19
, strongly coiled and fixed to intestine and septa by connective tissue, extending 1–4 segments backwards; muscular duct narrower and shorter (1/4) than glandular part. Penial setae
a
and
b
of both
17
and
19
, in separate follicles that join to form an ovoidal muscle pouch; these pouches fixed by muscular stripes to lateral walls (one fiber) and to the floor (one or two fibers per pouch). Further retractor muscles in 16/17 and 18/19, extending from mid-ventral line to dorso-lateral walls; mid-ventral floor in segments
16–18
thicker. In each follicle, one undeveloped extra seta present.
Ovaries one pair, large, on the floor of
13
, with bushy coral shape and numerous eggs not in rows; female funnels one pair in
13
, at both sides of mid-ventral line. Two pairs of similar-sized spermathecae discharging in 7/8 and 8/9, ampulla and duct in the respective posterior segment, diverticulum in the anterior one; diverticulum sessile, discoidal, tightened to the parietes and with the overall appearance of a cabbage; duct wider and shorter than the elongated ampulla, which narrows in the middle part (
Fig. 1
B). Length of spermathecae
2 mm
. Spermathecal setae embedded in ovoidal pouches of muscular tissue fixed to lateral parietes by muscular stripes. Two follicles within pouches, no extra setae observed.
Etymology.
The name of the species is dedicated to the Tojolabal people who inhabit the region of Montebello lakes and other nearby zones, in the highlands of the state of Chiapas.
Remarks.
R. tojolabala
belongs to the group of species with last hearts in
12
and quincuaxial setae. Being holandric it is separated from the metandric
R. guatemalana
,
R. balantina
,
R. tecumumami
,
R. americana
,
R. lavellei
and
R. vulcanica
; by having two pairs of seminal vesicles it is separated from
R. irpex
(one pair), although both species share the dorsal calciferous glands in segments
7–11
. The quincuaxial arrangement of setae separates it from the other holandric species of the genus like
R. sauerlandti
,
R. stadelmanni
,
R. strigosa
, R,
eiseni
and
R. microscolecina
, sharing with the last three species the shape of spermathecae. From the quincuaxial
R. lasiura
it is also separated because, after the revision of one
paratype
(see further on), this last species turned out to be metandric as was assumed by
Gates (1962)
. This species has previously been referred to as "
Ramiellona
sp.
nov.
28" (
Fragoso 1993
), "
Ramiellona
sp.
nov.
13" (
Fragoso 2001
), and "
Ramiellona
sp.
nov.
14" (Fragoso 2007;
Fragoso & Brown 2007
).