A review of the hyperiidean amphipod superfamily Lanceoloidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea)
Author
Zeidler, Wolfgang
text
Zootaxa
2009
2009-02-04
2000
1
117
journal article
11755334
Genus
Microphasma
Woltereck, 1909
Microphasma
Woltereck, 1909: 153
.
Pirlot 1929: 52
. Stephenson &
Pirlot 1931: 539
.
Bowman & Gruner 1973: 17
.
Vinogradov
et al
. 1982: 105
.
Type
species.
Microphasma agassizi
Woltereck, 1909
by monotypy.
The
unique
type
, a female measuring about
6.5 mm
(according to Woltereck’s figure), could not be found in any major
European
museum or in the USNM and is considered lost.
Fortunately
, this is a very distinctive species, readily distinguished by
Woltereck’s
description and figure.
The
type
locality is the eastern tropical
Pacific
, off
Peru
[
11º20’S
88º55’W
];
Albatross
Stn. 4663
.
Diagnosis.
Body length of females up to 9.0 mm, of males up to 8.0 mm. Head without rostrum. Eyes small, poorly discernable. Antennae 1 relatively short; in female slightly shorter than head and first pereonite combined, slightly longer in male. Antennae 2 slightly shorter than A1 with enlarged antennal gland. Mandibles with body narrowed distally; palp as long as body, third article only marginally shorter than second. Gnathopoda simple. Pereopods 3–5 subchelate with dactylus closing against distally broadened propodus. Pereopods 6 & 7 simple.
Monospecific.
Sexual dimorphism.
Males are readily distinguished from females by relatively larger first antennae that are as long as the head and first two pereonites combined if measured ventrally. Males also have small genital papillae, medially near the base of the seventh pereopods and in females the pereon is slightly more inflated.
Remarks.
This is a very distinctive genus, readily distinguished by the subchelate pereopods 3–5. It is very similar to
Microphasmoides
Vinogradov, 1960
, especially in the general habitus, antennae and structure of the mouthparts, differing mainly in that pereopods 3 & 4 are simple in
Microphasmoides
.
Microphasma
is similar to
Lanceola
in the general structure of the mouthparts but the second antennae are similar to that found in
Chuneola
in that they have an enlarged antennal gland.