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Bu.touGu, W. S. 1960. Practical invertebrate anatomy. 2nd ed. London: Macmillan.

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FiscHER, P. H., DuvaL, M. & Rarry, A. 1933. Etudes sur les échanges respiratoires des littorines. Archives de zoologie

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Koun, A. J. 1960a. Ecological notes on Conus (Mollusca: Gastropoda) in the Trincomalee region of Ceylon. Annals and

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Konn, A. J. 1960b. Spawning behaviour, egg masses and larval development in Conus from the Indian Ocean. Bulletin of

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(continued inside back cover)

ANNALS OF THE SOUTH AFRICAN MUSEUM

ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM

Volume 103 +#£4Band

May 1993 Mei

Part 2 Deel

FOUR NEW STREPTOCEPHALUS

(CRUSTACEA, BRANCHIOPODA,

ANOSTRACA) SPECIES

FROM SOUTH-EASTERN AFRICA

MICHELLE HAMER

C. C. APPLETON

Cape Town Kaapstad

The ANNALS OF THE SOUTH AFRICAN MUSEUM

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D2071

FOUR NEW STREPTOCEPHALUS

(CRUSTACEA, BRANCHIOPODA, ANOSTRACA)

SPECIES FROM SOUTH-EASTERN AFRICA

MICHELLE HAMER

C. C. APPLETON

Department of Zoology & Entomology, University of Natal, Pietermaritzburg, Natal,

South Africa

(With 8 figures)

[MS accepted 23 November 1992]

ABSTRACT

Four new Streptocephalus species (S. bidentatus, S. dendrophorus, S. spinicaudatus and S. bour-

quinii) are presented. The morphology of the male antennae, frontal appendage and cercopods is used

to separate species and this, together with the external egg morphology, is described and illustrated.

All four species appear to be restricted to the eastern region of southern Africa. Three resemble

known species from South Africa and can be allocated to groups that include species with similar

antennal and frontal appendage morphology. The fourth species has male antennal morphology

similar to the New World S. similis, but also shares some characters with a southern African species

group.

CONTENTS

PAGE

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DISCUISSIO TI area a eee Fee EE ee OT SUSE Ss TRIS GN eat cola rane ea es 179

INCKNOWLEU SEMEN ES ee semncm cece Ge ae wtastat siaes centeionsssmeleeanscioamaeceerce nt came 180

RYT RSI SI8 Ce aadacria nee HEC OR Hoe acne are etn SE MORADaC Sana te dat Haria tn HAA BEM Eats Mri hcian cuamaat 181

INTRODUCTION

The streptocephalids are a monogeneric anostracan family characterized by the

male second antenna being a two-jointed structure with an enlarged median process

terminating in a cheliform ‘hand’. The genus includes about 50 species recorded from

temporary freshwater pools in Eurasia, Africa and North America (Brtek 1974). A

review of the southern African Branchiopoda by Barnard (1929) included 13 species

of Streptocephalus. Subsequent to this, the African members of the genus were largely

neglected. As part of an ongoing project on the Anostraca, 17 streptocephalid species

from southern Africa were reviewed and divided into nine species groups comprising

species that share male antennal and frontal appendage characteristics. During the

examination of museum and other material collected in Zululand, the Kruger National

167

Ann. S. Afr. Mus. 103 (2), 1993: 167-181, 8 figs.

168 ANNALS OF THE SOUTH AFRICAN MUSEUM

Park, Transkei and Swaziland, specimens were found that closely resemble known

species but in which a few important characters showed constant differences from the

original descriptions. These specimens represent new species and they are described

below. The four new species occur allopatrically from the species to which they are

closely related. Streptocephalus bidentatus, S. spinicaudatus, S. dendrophorus and

S. bourquinii, described here, are each allocated to a species group.

MATERIALS AND METHODS

Anostracans were collected in north-eastern Natal and the Kruger National Park

using a hand-held dip net, the size and mesh of which depended on water depth, pool

size and the density of pool vegetation. Specimens were preserved in 70 per cent

ethanol. Drawings were done using a Wild M-—5 dissecting microscope and drawing

tube. Dissected antennae were washed in distilled water, fixed in a 2 per cent osmium

tetroxide and phosphate buffer solution for one hour before being dehydrated in a

graded ethanol series. Specimens were then critical point dried, mounted on stubbs

and coated with 20 nm of gold for scanning electron microscopical observation in a

Hitachi S-570 microscope at accelerating voltage of 10 kV. Eggs taken from the brood

pouch of preserved females were rinsed in distilled water, dried at 60°C for 24 hours

before being mounted on stubbs, coated and observed as for the antennae.

The terminology used for the different male antennal parts follows Brendonck

(1990) and that used to describe the frontal process of S. dendrophorus is from Belk &

Pereira (1982). The terminology used to describe egg morphology is from Brendonck

(1992).

Measurements were made using a graticule and are presented as total body length

(mean + standard deviation, or simply the mean and range if n < 10) from the front

of the head (excluding antennae) to the tip of the cercopods. Antennal length was

measured by totalling the length of the median antennal process from the head to the

base of the hand, and the length from the base of the hand, in a direct line, to the

apex of the thumb.

The material will be deposited at the South African Museum (catalogue numbers

SAM-A40820 to SAM—A40833).

TAXONOMIC DESCRIPTIONS

Family Streptocephalidae Daday, 1910

Streptocephalus bidentatus sp. nov.

Figs 1A—C, 2A-C

Type material

Holotype. SAM-—A40820, adult male (14,2 mm); collected 5 November 1990, by

M. Hamer in a large (approx. 20 X 15 m) temporary pool south of Skukuza, Kruger

National Park (25°03’S 31°38’E).

Paratypes. SAM—A40821, remainder of material from same locality, 28 males

(14,7 + 4,2 mm), 26 females (14,8 + 7,5 mm).

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA 169

Fig. 1. Streptocephalus bidentatus sp. nov. A. Lateral view of left antenna of male. B. Dorsal view

of frontal appendage. C. Dorsal view of male cercopods. Bar scales=1mm. Abbreviations:

f= finger, Ip = lateral process, mp = median antennal process, pr = projection, s = spur, th = thumb.

Other material

SAM-40822, 1 male (12,2 mm); collected from a pool in Swaziland, Hlane Game

Reserve, 3km from northern boundary (26°20’S 31°E) by T. Konstant. SAM-

A40823, 18 males (9,3 + 4,2 mm), 15 females (9,2 + 5,3 mm); collected in the

Kruger National Park, pools near Nhlanguleni (24°42’S 31°38’E), by M. Hamer,

October 1990. SAM-A40824, 21 males (12,7 + 1,0 mm), 9 females (12,9 mm, range:

9,8-14,0 mm); collected in the Kruger National Park, along Pumbe-Mozambique

fence (24°14’S 31°57’E), by M. Hamer, 26 October 1990. SAM-A40825, 13 males

(12,3 + 7,0 mm); collected in the Kruger National Park, 3 km north of Nkokodzi

(23°17'S 31°20’E), by M. Hamer, October 1990. SAM-A40826, 47 males (13,6 +

11,8 mm), 9 females (14,3 mm, range = 12,0-14,9 mm); collected from a temporary

pool on the Makatini Flats (27°24’S 32°10'E), north-eastern Natal by M. Hamer in

October 1987.

170 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 2. Streptocephalus bidentatus sp. nov. A. Medial view of right antenna of male. X 31,5.

B. Medial view of detail of teeth on dorsal margin of finger. x 180. C. Egg. x 315. Abbreviations:

bt = basal tooth, pr = projection.

Description of male

Antenna. Lateral process (Ip) slender, curved, tapered and apically subacute

(Fig. 1A). Median process of antenna (mp) of moderate length (ratio to body length

0,32 : 1). Proximal anterior region of thumb (th) with prominent projection (pr) on

dorsal margin (Figs 1A, 2A). Distal region with distinct bend, long, slender and api-

cally acute (Figs 1A, 2A). Angle between proximal and distal regions of anterior part

of thumb approx. 125°. Slender spur (s) of moderate length, separated from anterior

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA 171

part of thumb by two, occasionally three, rounded teeth of unequal size (Fig. 1A).

Finger (f) about one-half length of thumb, dorsally curved, with apex slightly recurved

and subacute. Dorsal margin of finger with digitiform proximal tooth, followed by

larger, roughly triangular distal tooth with small, digitiform tooth basally (bt) on

medial surface (Fig. 2A, B).

Frontal appendage moderate length, narrow, apically acute (Fig. 1B).

Cercopods. Long (ratio to body length 0,23: 1) with outer margins convexly

curved. Plumose setae along margins, replaced by strong, widely spaced spines on

distal third of inner margin (Fig. 1C).

Egg morphology

Egg shell with isolated, lip-like units of variable size and shape, each consisting of

an elongated central depression, surrounded by a broad, rounded rib with rugose

patterning (Fig. 2C).

Differential diagnosis

The hand region of S. bidentatus closely resembles that of S. macrourus Daday

and S. vitreus Brauer, particularly in the shape of the finger and thumb, and the two

rounded teeth separating the anterior region of the thumb and the posterior thumb

spur. In S$. macrourus, however, the tooth on the dorsal margin of the finger is large

and single, with a flattened appearance in lateral view and a small, basal digitiform

tooth. Streptocephalus vitreus shares the presence of two teeth, the distal with a small

basal tooth, with S. bidentatus, but the shape and size of these teeth distinguish the

two species. Although there is intraspecific variation in the teeth on the dorsal margin

of the finger of the S. vitreus specimens examined, the proximal tooth is always much

lower and apically more rounded than in S. bidentatus. The distal tooth is also lower

in S. vitreus and does not have a triangular shape. There is no variation in the shape

and size of the teeth of the S. bidentatus specimens examined. In addition, the cerco-

pods of S. vitreus have plumose setae along the entire inner margin and the distal

region of the telsonic segment has a pair of pointed processes that are absent in

S. bidentatus.

The presence of a third tooth between the anterior region of the thumb and spur

is not a significant character. It occurs in some individuals in a population, as in both

S. macrourus and S. vitreus.

Distribution

In addition to the localities already mentioned, S. bidentatus has also been col-

lected from Mkuzi and Ndumu game reserves in north-eastern Natal and from Mala

Mala Game Reserve in the eastern Transvaal. This species appears to be confined to

the north-eastern region of South Africa and Swaziland, between 23° and 28°S and

32°30’ and 31°20’E, but the northern limits of its distribution are uncertain.

Etymology

The specific name describes the two rounded teeth separating thumb and spur.

This character is unique to the closely related S. macrourus—S. vitreus—S. bidentatus

group of species.

172 ANNALS OF THE SOUTH AFRICAN MUSEUM

Streptocephalus dendrophorus sp. nov.

Figs 3A—C, 4A, B

Type material

Holotype. SAM—A40827, 1 male (16,6 mm); collected from the vegetated peri-

pheral regions of a rain-filled temporary pool on the Makatini Flats (27°24'S 32°10’E),

by M. Hamer in October 1987.

Paratypes. SAM-—A40828, 2 males, one with antennae and frontal appendage

removed (17,0 and 16,0mm); 1 male (6,2 mm), antennae not fully developed;

collected from same locality as holotype.

Male

Antenna. Lateral process (Ip) curved inwards, proximally broad, tapering to a

narrow apex (Fig. 3A). Median process of antenna (mp) of moderate length (ratio to

“4

(

‘

\ /

Fig. 3. Streptocephalus dendrophorus sp. nov. A. Lateral view of frontal appendage and left antenna

of male. B. Ventral view of basal processes. C. Dorsal view of male cercopods. Bar scale =1 mm.

Abbreviations: a= arm, bp = basal processes, f= finger, lp = lateral process, mp = median antennal

process, pa= papillae, s=spur, th=thumb, tr=trunk, 1A =anterior branch, 1LV = latero-ventral

branches.

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA 173

body length 0,35:1). Pair of small processes (bp) with irregular inner margin, basal

and ventral to median processes of antennae (Fig. 3B). Basal region of median

process with 2-3 papillae (pa) on anterior margin (Fig. 3A, B), followed by 4-6

similar structures medianly at first bend. Anterior region of thumb (th) proximally

folded (Fig. 4A), distal region slender, dorsally curved and apically pointed. Angle

between proximal and distal region of anterior part of thumb approx. 170° (Fig. 3A).

Angle between triangular spur (s) and anterior part of thumb approx. 90°. Finger (f)

short (about one-half length of thumb), proximally broad and dorsally curved, with

recurved acute apex (Figs 3A, 4A). Anterior margin of finger with long, convex,

ridge-like tooth with anterior hook-like projection (Fig. 4A).

Frontal appendage. Long (ratio to body length 0,39 : 1) and complex. Trunk (tr)

dividing into two lateral branches (1LV/LV) and a third anterior branch (1A) about a

one-quarter way along total length. Branch 1A bifurcate with each arm (a) tapered

and about one-third length of frontal appendage. Long digitiform processes at base of

trunk, along proximal half of ventral margin of each LV branch and just proximal to

the division of 1A. Apically two LV branches and two arms narrow and with papillate

processes (Fig. 3A).

Cercopods. Moderate length (ratio to body length 0,21 : 1), straight, tapered and

with plumose setae along both margins (Fig. 3C).

Egg morphology

Egg shell with large, simple, 4—6 sided fields, separated from neighbouring fields

by thin, sharp ribs (Fig. 4B).

Differential diagnosis

Streptocephalus dendrophorus closely resembles the southern African S. clado-

phorus Barnard. The frontal appendage, cercopods and basal processes of the two

Fig. 4. Streptocephalus dendrophorus sp. nov. A. Medial view of hand region of male antenna.

x 72. B. Egg. X 315. Abbreviations: f= finger, s = spur, th = thumb.

174 ANNALS OF THE SOUTH AFRICAN MUSEUM

species are the same, and neither species has a tooth between the anterior region of

the thumb and the spur. The most important differences between the two species,

however, are in the hand region of the antenna. The angle between the anterior

thumb and posterior spur is more acute and the spur narrower and more ventrally

curved in S. cladophorus. Additional differences in the finger (long, slender and

almost straight in S. cladophorus) and in the teeth on the anterior margin of the finger

(a small rounded tooth or two unequally sized teeth in S. cladophorus) indicate two

distinct species.

Distribution

Streptocephalus dendrophorus has, to date, only been collected from Mkuzi and

Ndumu game reserves and the Makatini Flats in north-eastern Natal, between 26°50’

and 27°35’S and 32°05’ and 32°40’E.

Etymology

The specific name describes the elaborate, tree-like frontal appendage.

Streptocephalus spinicaudatus sp. nov.

Figs 5A-D, 6A-—C

Type material

Holotype. SAM—A40829, 1 male (22,5 mm); collected at Umtata Dam, Transkei

(31°30'S 28°36’E) by M. Schramm in September 1990.

Paratypes. SAM—A40830, 11 males (22,6 + 1,1mm), 3 females (21,5; 18,3;

21,3 mm), two with eggs in brood pouch, one with brood pouch damaged; collection

data as for holotype.

Other material

SAM-A40831, 2 males (17,4, 17,3 mm) and 1 female (18,3 mm); collected at

Sterkstroom (31°33’S 26°32’E) by J. Omer-Cooper in 1954.

Male

Antenna. Lateral process (Ip) curved medianly, stout and apically subacute

(Fig. SA). Median antennal process (mp) of moderate length (ratio to body length

0,24 : 1), curved with 2—4 small papillae on medial surface distal to first bend. Thumb

(th) with proximal fold produced to form prominent projection (pr) on anterior

margin (Fig. 5A). Distal region of thumb with bend (Fig. 5A), after which thumb

slender and apically acute (Figs SA, 6A). Spur (s) moderate length, apically subacute,

and separated from anterior region of thumb by large, triangular tooth (Fig. SA).

Angle between proximal and distal regions of anterior part of thumb approx. 130°.

Finger (f) two-thirds length of thumb, dorsally curved with blunt, slightly indented

apex. Anterior margin of finger with proximal digitiform, apically rounded tooth.

Distal tooth larger and triangular (Fig. 6A, B).

Frontal appendage. Moderate length, apically rounded with small median inden-

tation (Fig. 5B).

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA ATS

Fig. 5. Streptocephalus spinicaudatus sp. nov. A. Lateral view of left antenna of male. B. Dorsal

view of frontal appendage. C. Dorsal view of male cercopods. D. Dorsal view of abdominal seg-

ments 2-8 showing spination. Bar scale=1mm. Abbreviations: f= finger, Ip =lateral process,

mp = median antennal process, pr = projection, s = spur, th = thumb.

Cercopods. Moderate length (ratio to body length 0,16 : 1), tapered with outer

margins bent convexly. Plumose setae on outer margins, inner margins with patch of

setae proximally, followed by stout, closely set spinous processes of unequal length.

Distally these more widely spaced (Fig. 5C).

Abdomen. Posterior margins of abdominal segments 2-7 with spines. Seg-

ments 2—4 with lateral spines only, segment 5—7 with more numerous but smaller

dorsolateral spines (Fig. 5D).

Egg morphology

Egg surface with folded appearance, irregular fields sunken with 4—5 sides, separ-

ated by rounded ribs of moderate width (Fig. 6C).

176 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 6. Streptocephalus spinicaudatus sp. nov. A. Medial view of right antenna of male. X 31,5.

B. Medial view of detail of teeth on dorsal margin of finger. xX 117. C. Egg. x 315. Abbreviations:

f = finger, pr = projection, th= thumb.

Differential diagnosis

Streptocephalus spinicaudatus shares many morphological characters with the

eastern Cape species S. dregei Sars. The latter species is, however, distinct from

S. spinicaudatus in that it has a pair of basal processes ventral to the antennae, a large

triangular tooth on the medial surface of the median process just proximal to the hand

region, a single tooth on the anterior margin of the finger, slightly smaller abdominal

spines, and more regular spinous processes on the inner margin of the cercopods. No

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA Lie.

intraspecific variation has been observed in either the S. dregei or the S. spinicaudatus

specimens examined.

Distribution

Streptocephalus spinicaudatus has only been collected from two localities in the

eastern Cape and Transkei region of southern Africa.

Etymology

The specific name describes the spinous nature of the abdomen and inner margin

of the cercopods.

Streptocephalus bourquinii sp. nov.

Figs 7A-D, 8

Type material

Holotype. SAM—A40832, 1 male (24,3 mm); left antenna and cercopods slightly

damaged; collected in north-eastern Natal, Hluhluwe Game Reserve, Manzibomvu

perennial stream (28°03’00"S 32°07'15"E), by Dr O. Bourquin, 28 April 1969.

Paratype. SAM—A40833, 1 female (25,5 mm), from the same locality.

Other material

BMNH 1963.10.1.1, 1 male (7,0 mm) and 1 female (7,5 mm); specimens col-

lected from Tshaneni in Swaziland (26°01’S 31°46’E) in 1963.

Male

Antenna. Lateral process (Ip) curved, apically blunt (Fig. 7A). Median antennal

process (mp) of moderate length (ratio to body length 0,36 : 1), with 3—4 triangular

processes (p) (Fig. 7A, B), followed by a larger irregular process (p2) just distal to

first bend on anterior margin (Fig. 7B). Base of thumb (th) folded, with fold produced

to form a prominent, narrow, pointed projection (pr) on anterior margin (Fig. 7A,

B). Distal region of thumb bent dorsally and narrow, apically acute. Angle between

proximal and distal parts of anterior region of thumb approx. 100°. Spur (s) short and

tapered. Angle between spur and anterior region of thumb smooth and wide (approx.

130°) (Fig. 7A). Finger (f) about four-fifths length of thumb, tapered and with

recurved and acute apex (Fig. 7A, B). Anterior margin of finger with large, roughly

triangular tooth proximally, followed by long, ridge-like tooth (Fig. 7B).

Frontal process. Short, apically rounded with median indentation (Fig. 7C).

Cercopods. Moderate length (ratio to body length 1 : 0,16). Straight, tapered and

with plumose setae along both margins (Fig. 7D). Setae short at apices, particularly in

BMNH 1963.10.1.1 specimens.

Egg morphology

Simple, irregular polygonal fields with 4—5 sides, separated from neighbouring

fields by broad, rounded, crenulate ribs (Fig. 8).

178 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 7. Streptocephalus bourquinii sp. nov. A. Lateral view of left antenna of male. B. Medial view

of hand region of antenna. C. Dorsal view of frontal appendage. D. Dorsal view of male cercopods.

Bar scale 1mm. Abbreviations: f= finger, lp=lateral process, mp=median antennal process,

p2 = irregular process, p = triangular processes, pr = projection, pr = projection, s = spur, th = thumb.

Differential diagnosis

Streptocephalus bourquinii shares the following characteristics with the New

World species S. similis Baird: a bilobed, rounded frontal appendage, the absence of a

process between the anterior region of the thumb and spur, and the shape of the

thumb and finger. The triangular and irregular processes on the median process are,

however, absent in S. similis. Streptocephalus bourquinii has two teeth on the anterior

margin of the finger, whereas S. similis has three, and these teeth differ in shape

between the two species (see Moore 1958). Streptocephalus bourquinii also lacks the

spines along the distal half of the inner margin of the cercopods of S. similis.

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA 179

Fig. 8. Streptocephalus bourquinii sp. nov. Egg. x 315.

Distribution

Streptocephalus bourquinii was also collected in 1986 and 1987 from Fanies Island

(28°10’S 32°25’E) and False Bay Park (27°55’S 32°20’E) in the St Lucia area of north-

eastern Natal, but these specimens were destroyed. The other localities of Swaziland

and Hluhluwe indicate that this species is restricted to the north-eastern region of

southern Africa.

Etymology

Streptocephalus bourquinii is named after Dr O. Bourquin of the Natal Parks

Board, who collected the type specimens.

DISCUSSION

The seventeen southern African streptocephalid species can be divided into nine

species groups based on similarities in antennal and frontal appendage morphology.

Three of the four species described herein show a large degree of morphological simi-

larity to known species. This allows for easy allocation to existing species groups.

Streptocephalus bidentatus belongs to the same group as S. macrourus and the north

and east African S. vitreus. The elaborate frontal appendage and antennal hand

region of S. dendrophorus clearly place it with S. cladophorus. Streptocephalus spini-

caudatus, because of its cercopod setation, abdominal processes and hand region, can

be placed with S. dregei and S. cirratus Daday. Streptocephalus bourquinii does not

show any distinct similarity to other African species. It can, however, be allocated to

the rather broad species group that includes S. cafer Lovén, S. indistinctus Barnard,

and the Madagascan species, S. spinosus Daday and S. distinctus Thiele, on the basis

180 ANNALS OF THE SOUTH AFRICAN MUSEUM

of the shape of the thumb and finger and the projections on the median antennal

process. If this species group is split, as it perhaps should be, into S. cafer—S. indistinc-

tus and a separate group comprising S. spinosus—S. distinctus, S. bourquinii would not

belong to either group. The latter closely resembles the New World species S. similis,

but whether the similarity is a result of dispersal and subsequent speciation, or of

parallel evolution, is debatable.

The presence of a number of species with very similar morphologies indicates that

dispersal and/or successful colonization is not as common a phenomenon amongst the

streptocephalids as would be expected in animals with drought-resistant, easily-

transportable eggs. Gene flow between temporary pools was found by Fugate (1990)

to be restricted in the American genus Branchinecta. Local adaptations resulting in

speciation may thus be common in such habitats and this appears to have been the

case in the African streptocephalids, as shown by the species described here.

The characters used to differentiate between species are probably related to

specific mate recognition. Belk (1991) suggested that the female responds to tactile

cues provided by the male antennae, frontal appendages and various forms of body

armature during mate selection. The hand region of the antenna, in particular,

appears to first reflect changes related to speciation in the African species examined.

In the case of the species described here, the teeth on the anterior margin of the finger

are the most striking indicators of speciation. Cercopod setation also seems to change

early in relation to speciation and it is possible that this structure is also involved in

mate selection. The frontal appendage, strangely enough, is a conservative character

among those species described and appears to change at a slower rate than the anten-

nae and cercopods. This is clearly shown by S. dendrophorus and S. cladophorus. Egg

morphology does not always indicate separate species or relationships between

species. For example, there is very little difference between the eggs of S$. bidentatus

and those of S. vitreus from the Sudan (Brendonck 1992), but the eggs of S. spinicau-

datus are quite different from those of S. dregei. The large amount of intraspecific

variation and overlap in egg morphology between species groups makes this an unre-

liable character in streptocephalid taxonomy.

ACKNOWLEDGEMENTS

The first author is in receipt of a Foundation for Research Development post-

graduate bursary. The co-operation of the Natal Parks Board, in particular Mike Coke,

and the National Parks Board is acknowledged. Dr Andrew Deacon’s assistance with

collecting in the Kruger National Park is much appreciated. Mike Schramm (Univer-

sity of Transkei) is thanked for collecting specimens in Umtata. The staff of the

Electron Microscope Unit of the University of Natal, Pietermaritzburg, assisted with

the scanning electron micrographs. Dr Luc Brendonck and Dr Denton Belk are

acknowledged for their valuable comments on the new species.

NEW SPECIES OF STREPTOCEPHALUS FROM SOUTH-EASTERN AFRICA 181

REFERENCES

BarnarD, K. H. 1929. Contributions to the Crustacean fauna of South Africa. A revision of South

African Branchiopoda (Phyllopoda). Annals of the South African Museum 29 (5): 181-272.

BeELK, D. 1991. Anostracan mating behaviour: a case of scramble competition polygyny. Jn: BAUER,

R. T. & Martin, J. W. eds. Crustacean sexual biology: 111-125. New York: Columbia Univer-

sity Press.

Berk, D. & Pereira, G. 1982. Thamnocephalus venezuelensis, new species (Anostraca: Thamno-

cephalidae), first report of Thamnocephalus in South America. Journal of Crustacean Biology

2 (2): 223-226.

BreNpDonck, L. 1990. Redescription of the fairy shrimp Streptocephalus proboscideus (Frauenfeld,

1873) (Crustacea: Branchiopoda: Anostraca). Bulletin de l’Institute Royal des Sciences Naturelles

de Belgique. Biologie 59 [1989]: 49-57.

BreENDONCK, L. 1992. Study of the biology of large freshwater branchiopods with special reference to

the fairy shrimp Streptocephalus proboscideus (Frauenf.) (Crustacea: Branchiopoda: Anostraca).

Ph.D. thesis, University of Gent, Belgium.

Brtexk, J. 1974. Zwei Streptocephalus Arten aus Afrika und einige Notizen zur Gattung Streptocepha-

lus. Annotationes Zoologicae et Botanicae 96: 1-9.

Dapay, E. 1910. Monographie systematique des Phyllopodes Anostraces. Annales des Sciences

Naturelles, Zoologie (4° serie) 11: 91-489.

Fucate, M. 1990. Population structure and gene flow in Branchinecta. (Abstract.) American Zool-

ogist 30 (4): 72A.

Moore, W. G. 1958. On the occurrence of Streptocephalus similis Baird in Mexico and the United

States. Journal of Washington Academy of Sciences 48: 169-175.

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6. SYSTEMATIC papers must conform to the International code of zoological nomenclature (particu-

larly Articles 22 and 51).

Names of new taxa, combinations, synonyms, etc., when used for the first time, must be followed

by the appropriate Latin (not English) abbreviation, e.g. gen. nov., sp. nov., comb. nov., syn. nov.,

etc.

An author’s name when cited must follow the name of the taxon without intervening punctuation

and not be abbreviated; if the year is added, a comma must separate author’s name and year. The

author’s name (and date, if cited) must be placed in parentheses if a species or subspecies is trans-

ferred from its original genus. The name of a subsequent user of a scientific name must be separated

from the scientific name by a colon.

Synonymy arrangement should be according to chronology of names, i.e. all published scientific

names by which the species previously has been designated are listed in chronological order, with all

references to that name following in chronological order, e.g.:

Family Nuculanidae

Nuculana (Lembulus) bicuspidata (Gould, 1845)

Figs 14-15A

Nucula (Leda) bicuspidata Gould, 1845: 37.

Leda plicifera A. Adams, 1856: 50.

Laeda bicuspidata Hanley, 1859: 118, pl. 228 (fig. 73). Sowerby, 1871: pl. 2 (fig. 8a—b).

Nucula largillierti Philippi, 1861: 87.

Leda bicuspidata: Nicklés, 1950: 163, fig. 301; 1955: 110. Barnard, 1964: 234, figs 8-9.

Note punctuation in the above example:

comma separates author’s name and year

semicolon separates more than one reference by the same author

full stop separates references by different authors

figures of plates are enclosed in parentheses to distinguish them from text-figures

dash, not comma, separates consecutive numbers.

Synonymy arrangement according to chronology of bibliographic references, whereby the year is

placed in front of each entry, and the synonym repeated in full for each entry, is not acceptable.

In describing new species, one specimen must be designated as the holotype; other specimens

mentioned in the original description are to be designated paratypes; additional material not regarded

as paratypes should be listed separately. The complete data (registration number, depository, descrip-

tion of specimen, locality, collector, date) of the holotype and paratypes must be recorded, e.g.:

Holotype

SAM-—A13535 in the South African Museum, Cape Town. Adult female from mid-tide region, King’s Beach, Port Eliza-

beth (33°51'S 25°39’E), collected by A. Smith, 15 January 1973.

Note standard form of writing South African Museum registration numbers and date.

7. SPECIAL HOUSE RULES

Capital initial letters

(a) The Figures, Maps and Tables of the paper when referred to in the text

e.g. ‘. . . the Figure depicting C. namacolus .. .’: ‘. . . in C. namacolus (Fig. 10) .. .’

(b) The prefixes of prefixed surnames in all languages, when used in the text, if not preceded by

initials or full names

e.g. DuToit but A.L.du Toit; Von Huene but F. von Huene

e.g. Therocephalia, but therocephalian

Punctuation should be loose, omitting all not strictly necessary

Reference to the author should preferably be expressed in the third person

Roman numerals should be converted to arabic, except when forming part of the title of a book or

article, such as

‘Revision of the Crustacea. Part VIII. The Amphipoda.’

Specific name must not stand alone, but be preceded by the generic name or its abbreviation to initial

capital letter, provided the same generic name is used consecutively. The generic name should

not be abbreviated at the beginning of a sentence or paragraph.

Name of new genus or species is not to be included in the title; it should be included in the abstract,

counter to Recommendation 23 of the Code, to meet the requirements of Biological Abstracts.