A New Genus Of Tetragnathid Spiders From Papua New Guinea (Aranei, Tetragnathidae)
Author
Marusik, Y. M.
Author
Omelko, M. M.
text
Vestnik Zoologii
2017
Vestn. Zool.
2017-06-27
51
3
203
214
http://dx.doi.org/10.1515/vzoo-2017-0027
journal article
10.1515/vzoo-2017-0027
97b55f6c-b168-4147-ba1f-771aef3a9a8d
2073-2333
6454189
0BB9A61D-45CB-4A36-87F3-B141517DD1A6
Nediphya
gen. n.
urn:lsid:zoobank.org:act:
55D4DFDB-361F-4E62-AD8F-BB81FDD1FC12
T y p e s p e c i e s.
Nediphya lehtineni
sp. n
.
Diagnosis. The new genus differs from all
Tetragnathidae
by having eyes arranged in 3 rows (
figs 12–17
).
Nediphya
gen. n.
is most similar to
Diphya
(
figs 9–11
) by having heterogeneous eyes, a prolateral row of stiff setae on the tibia-tarsus of legs I–II, and a strong, large dorsal claw-like branch of the paracymbium. New genus can be distinguished by small anterior lateral eyes, not spaced with posterior eyes, low clypeus (less than diameter of AME),
vs
. ALE equal in size to PLE and PME, lateral eyes widely spaced, clypeus higher than diameter of AME in
Diphya
. In addition, the cephalic part of the carapace in
Nediphya
gen. n.
is unmodified (
fig. 12
) (slanted in
Diphya
(
fig. 11
)). The two genera can also be distinguished by the shape of the epiandrous plate and the number of fusules (only 2 pairs of fusules located in 2 pits in
Nediphya
gen. n.
(
fig. 25
)
vs
. about 2 dozen arranged in a transverse row in
Diphya
(cf. Marusik & Omelko, 2017)). Males of
Nediphya
gen. n.
can be recognized by having a strongly reduced ventral branch of the paracymbium (large and bilobed in
Diphya
,
fig. 33
) and the presence of a cymbial lobe (lacking in
Diphya
(
figs 32– 33
)), a filamentous and gradually rounded embolus (broad and twisted in
Diphya
). Females of two genera can be easily distinguished by the epigyne weakly sclerotized in new genus and well sclerotized in
Diphya
).
D e s c r i p t i o n. Small, male 2.50, females 2.42–3.10; carapace 1.14 long in male,
1.05–1.23 in
females. Carapace pear-shaped, rather high (
figs 1–2, 6–8
,
12–13,15
), with pattern composed of lateral or sublateral dark bands. Eyes in 3 rows (
figs 12–17
), AME in first row, ALE and PME in second, and PLE in third. ALE and AME subequal in size, ALE 1.5–2 times smaller than PME, clypeus small, less than 1 diameter of AME. Sternum shield like (
figs 3
,
19
) with slightly darkened margins. Chelicerae not enlarged, with 3 prolateral and 2–3 retrolateral teeth; distal teeth (
Dt
) large (
fig. 21
). Legs with annulations, tibia-tarsus of legs I and II with rows of stiff subdecumbent setae (
fig. 18
) forming a kind of “catching basket” (
figs 6–8
). Few macrosetae, 0–5 on each segment. Tarsi pseudosegmented (
fig. 24
). Coxae IV in male unmodified, lacking stridulatory teeth or ridges. Female palp with straight, untoothed claw (
fig. 12
). Abdomen patterned, pattern partly composed of white guanine spots in 2 species. Book lung opercula unmodified, lacking stridulatory ridges. Male spinnerets as in
fig. 23
. Colulus well developed with 4 setae (
fig. 23
). Epiandrous plate with 2 pits, each pit with pair of fusules.
Copulatory organs. Male palp with long femur (6 times longer than wide and about 1.4 times longer than patella + tibia); patella and tibia unmodified; cymbium almost round with retrolateral hollow (
Rh
), small antero-retrolateral lobe (
Cl
) connected by shallow fold (
Cf
) to paracymbium; paracymbium composed of small lateral branch (
Pl
) and large dorsal claw-like branch (
Pd
); bulb round in ventral view, hemispherical in lateral view, ventral side of bulb flat, almost entirely covered with broad ribbon-like semitransparent conductor (
Co
); tip of conductor with 3 processes (rounded retrolateral (
Cr
), sharply pointed prolateral (
Cp
) and weakly sclerotized median (
Cm
)); dorso-anterior part of conductor with furrow (
Fc
); embolus (
Em
) very long, filamentous, making 1.5 loops (
ca
540°), and entirely enclosed by the conductors fold.
Epigyne weakly sclerotized, with distinct median plate (
Mp
), copulatory opening indistinct; copulatory ducts (
Cd
) visible through integument, subparallel; 1–3 pairs of weakly sclerotized receptacles.
R e l a t i o n s h i p s. Although the modified eyes, spination of legs I and II with peculiar stiff setae forming a catching basket, lack of sexual dimorphism, small size and unmodified chelicera in
Nediphya
gen. n.
are similar to these in
Diphya
, the morphology of the copulatory organs is significantly different between the two genera.
Highly heterogeneous eyes are also known in
Pinkfloydia
Dimitrov et Hormiga, 2011
, but in that genus only the PME are strongly enlarged and larger than the lateral eyes.
The epiandrous plate in
Nediphya
(
fig. 25
) is similar to that in
Nanometa
(cf. fig. 87E in
Álvarez-Padilla & Hormiga (2011))
and
Dolichognatha pentagona
(Hentz, 1850 (cf.
fig. 31G
in
Álvarez-Padilla & Hormiga (2011))
with 2 isolated pit each bearing 4 fusules.
To date, prolateral rows of stiff setae on tibia-metatarsi of legs I and II are well documented in tetragnathids only in
Diphya
(Tanikawa, 1995; Marusik, 2017, Marusik et al., 2017), but can also be found in
Metellina orientalis
(Spassky, 1932)
and
M. kirgisica
(Bakhvalov, 1974)
(personal data) and in an unidentified genus and species from
Papua New Guinea
(
figs 52–54
).
The bulb in
Nediphya
is very similar to those illustrated of “
Orsinome
”
sarasini
Berland, 1924,
Nanometinae
sp. and
Nanometa
sp.
illustrated by (
Álvarez-Padilla & Hormiga (2011)
, as well as “
Orsinome
”
lagenifera
(Urquhart, 1888)
. Those species are from either
Australia
,
New Zealand
or Tasmania and all have a broad conductor hiding the tegulum as in
Nediphya lehtineni
and a filamentous embolus hidden partly or entirely by the fold of the conductor. In addition, those taxa all possess an anterolateral lobe of the cymbium (= CEMP or cymbial ectomedian process
sensu
Álvarez- Padilla and Hormiga (2011)) and a cymbial fold between the lobe and the dorsal branch of the paracymbium (= CEBP or cymbial ectobasal process
sensu
Álvarez-Padilla and Hormiga (2011))
. In addition to the similar bulb and cymbium morphology in the four species, they each have a well-developed ventral branch of the paracymbium bearing few setae; in
Nediphya lehtineni
sp. n.
the ventral branch of paracymbium is strongly reduced and lacks setae (
figs 35–39
). None of these four species has a modified eye pattern.
Females of “
Orsinome
”
sarasini
and
Nanometa
sp.
illustrated by Álvarez- Padilla and Hormiga (2011) have epigynes rather similar to that of
Nediphya lehtineni
sp. n.
The complicated morphology of the copulatory organs reflects the phylogenetic relationships between taxa much better than does somatic morphology and thus we consider that
Nediphya
gen. n.
belongs to
Nanometinae
Forster & Forster, 1999
sensu
Álvarez-Padilla & Hormiga (2011)
.
Nanometinae
is currently composed of the monotypic genera
Nanometa
Simon, 1908
(known from the female only (WSC 2017)) and
Pinkfloydia
Dimitrov et Hormiga, 2011
(
Álvarez-Padilla & Hormiga (2011)
.
Status of
Nanometinae
Forster & Forster, 1999
Forster & Forster (1999)
considered
Nanometinae
to be composed of
Nanometa
,
Orsiella lagenifera
(Urquhart, 1888)
(
Orsiella
is a
nomen nudum
and currently species misplaced in
Orsinome
) and
Eryciniolia
Strand, 1912
.
Álvarez-Padilla & Hormiga’s (2011)
concept of
Nanometinae
included only
Nanometa
,
Pinkfloydia
, misplaced “
Orsinome
”
sarasini
, and a single unplaced “
Nanometinae
sp.” It is unclear how
Álvarez-Padilla & Hormiga (2011)
recognized “
Nanometa
sp.
” or “
Nanometinae
sp.” without studying the
type
species,
N. gentilis
Simon, 1908
. The
type
species is known only by the verbal description of
Simon (1908)
from
Western Australia
and figures in
Dalmas (1917)
of the eye region and epigyne of a
New Zealand
specimen (WSC 2017).
Dalmas (1917)
studied Simon’s
type
and mentioned some differences between specimens from
New Zealand
and
Australia
. It is worth noting that
Roewer (1942: 1013)
erroneously indicated that
Nanometa gentilis
was described based on the female and known only from
Western Australia
, although
Simon (1908)
described both sexes and
Dalmas (1917)
reported specimens from
New Zealand
. These errors are repeated in
Platnick (2000
–2014) and the
World Spider Catalog (2017)
which are based on Roewer’s incorrect data.
The morphology of the copulatory organs of
Pinkfloydia
,
Eryciniolia
, and two misplaced
Orsinome
species
differ considerably from
Nanometa
sensu
Álvarez-Padilla & Hormiga (2011)
and, to our mind, cannot be considered in
Nanometinae
.
Distinguishing species of
Nediphya
gen. n.
Some species can be recognized by carapace pattern (
figs 2, 4, 6–8
,
12–15
). All species differ by spination and shape of epigyne (see diagnoses of the individual species).
Composition:
Nediphya lehtineni
sp. n.
(♂,
♀
),
N. hippai
sp. n.
(
♀
),
N. lyleae
sp. n.
, and
N. padillai
sp. n.
(
♀
), all from
Papua New Guinea
.
Etymology. The genus name is a combination of two letters from terra typica
Papua New Guinea
with
Diphya
and, in most Slavic languages, meaning “not
Diphya
”. The gender is feminine.