Taxonomy and distribution of irregular echinoids (Echinoidea: Irregularia) from Sri Lanka
Author
Arachchige, Gayashan M.
Author
Jayakody, Sevvandi
Author
Mooi, Rich
Author
Kroh, Andreas
text
Zootaxa
2019
2019-01-03
4541
1
1
100
journal article
27715
10.11646/zootaxa.4541.1.1
9c3fecf1-4e11-4c79-a908-e0a5abbaf3ca
1175-5326
2617460
B11E734C-218B-418C-84E6-719AB3C58AFF
Fibulariella angulipora
Mortensen, 1948
Figures 34
,
35
1948d
Fibularia
(
Fibulariella
)
angulipora
Mortensen
: p. 6.
1948b
Fibularia
(
Fibulariella
)
angulipora
Mortensen.
—Mortensen: p. 224–225; pl. 46: figs. 1–4, 12–14.
Material studied.
Ten denuded tests: WUSL/EI/132, EI/133, EI/144, EI/145, EI/146, EI/147, EI/148, EI/149, EI/ 150, and EI/151, from Etalai, Kalpitiya,
Sri Lanka
.
Description.
Shape and size
—Test oval, rounded or pointed at both ends, small size,
3.39–7.14 mm
TL, longer than broad, width 65–71% TL, height 43–53% TL; greatest height usually anterior to apical system; oral side convex; raised, rounded margin; aboral surface sloping slightly downward towards posterior end.
Apical system
—Subcentral, 41–51% TL from anterior margin; four small, circular gonopores, multiple small hydropores, not in groove, scattered over anterior portion of madreporic plate.
Ambulacra
—Petaloid area longer than half of TL, 66–71% TL; petaloid area width 40–46% TL; petals short, with 3–5 pore pairs in posterior paired petals, 3–4 pore pairs in anterior paired petals, 4–5 pore pairs in petal III; pores in posterior petals markedly triangular.
FIGURE 34.
Fibulariella angulipora
(WUSL/EI/164): A, aboral view; B, oral view; C, lateral view.
Peristome
—Medium-sized, 15–19% TL; usually rounded, width 13–17% TL; lies slightly anterior of centre, 40–47% TL from anterior margin.
Periproct
—Small, 8–9% TL; oval in outline, slightly elongate; situated closer to peristome than posterior edge, 17–23% TL from posterior margin.
FIGURE 35.
Distribution map of
Fibulariella angulipora
recorded in this study.
Geographic range.
Indo-West Pacific, from Andaman Sea (
Putchakarn & Sonchaeng 2004
) to Gulf of
Siam
and the Molucca Sea (
Mortensen 1948b
).
Bathymetric range.
15 m
(
Mortensen 1948b
).
Observed occurrence in
Sri Lanka
. The current study found only denuded tests of
F. angulipora
on the shore of Etalai, Kalpitiya, in north-western coasts of Sri Lanka (
Fig. 35
).
Remarks.
According to (
Mortensen 1948b: 225
), this species differs from the two other
Fibulariella
species,
F. acuta
and
F. oblonga
,
by the large, triangular pores in the petals.
F. angulipora
is recorded here for the first time from
Sri Lanka
. This supports
Mortensen's (1948b: 225)
suggestion that the specimen mentioned as
Fibularia volva
by H. L
Clark (1915)
was in reality
Fibulariella angulipora
, not
Fibularia volva
.