The new species is characterized by the unique shape of the antennule, antenna and maxilla. In addition, huge scales are present on the mouth tube and smaller scales are present on the base of the mouth tube. A row of small spines is present inside the sucker rim of the maxillule. A round dimpled structure occurs ventral to the male gonopore and the unique accessory copulatoiy structures are described

Avenant-Oldewage, Annemarié

Oldewage, W.H.

English

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S. Afr. 1. Zool. 1995,30(4) 197-199 A new species of Argulus (Crustacea: Branchiura) from a bony fish in Algoa Bay, South Africa Annemarie Avenant-Oldewage* and W.H. Oldewage Department of Zoology, Rand Afrikaans University, P.O. Box 524, Auckland Park, 2006 Republic of South Af"ica Received J December 1994; accepted 29 September 1995 The new species is characterized by the unique shape of the antennule, antenna and maxilla. In addition, huge scales are present on the mouth tube and smaller scales are present on the base of the mouth tube. A row of small spines is present inside the sucker rim of the maxillule. A round dimpled structure occurs ventral to the male gonopore and the unique accessory copulatory structures are described. + To whom correspondence should be addressed Three marine species of Argulus occur in South Africa. Two species were recorded by Barnard (1955), i.e. A. multipucola Bamard, 1955 from Richards Bay and A belone,. Van Kam-pen, 1909 from Natal, and A. kosus Avenant-Oldewage, 1994 from Kosi Bay. These species are clearly distinguishable from each other and from specimens recently donated by the Port Elizabeth Museum to the authors. A new species is there-fore described. Three female and one male Argulus were removed from a unicorn leatherjacket Aluterus monoceros (Linn., 1758) col-lected on 9 April 1991 close to the Port Elizabeth harbour in Algoa Bay and given to the Port EI izabeth Museum. The Argulus were fixed in 10% formalin and preserved in 70% propanol. The specimens were donated to the authors by Dr Malcolm Smale of the Museum. For microscopic study, the specimens were cleared in 90% lactic acid and drawn with the aid of a drawing tube attach-ment on a Zeiss Lab 18 microscope. Specimens are in the col-lection of the Albany Museum, Grahamstown, holotype no . . ' .. l~ . . ···l· . . ~. RAU 3A and paratype no. RAU 3B Argulus smale; n.sp. Adult female. General body shape ovoid (Figures I & 2) with paired incisions of antero-lateral carapace to form defined frontal region. Colour in formalin-fixed specimens yellowish with spermathecae dark brown. Body length of holotype 5,6 mm, paratypes 4, I mm and 4,0 mm respectively. Carapace comprising 74% of total body length. Body covered dorsally by carapace with lobes extending over all four pairs of swim-ming legs. Sinus in carapace, 24% of carapace length. Dor-sally, sinus exposing kidney-shaped lobe on fourth thoracic segment. Compound eyes small, colourless and situated in frontal region i.e. first 25% of carapace. Nauplius eye not visible. Abdomen broad with well-defined anal sinus along 61% of its length. Abdomen 31% of total length. Furcal rami minute, simple round structures with three to four setae each. Paired spermathecae situated anteriorly. Figure 1-2 Argulus smalei n,sp. female. Figure I dorsal view; Figure 2 ventral view. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2009).198 Ventral surface of carapace covered peripherally by numerous spines arranged in regular manner, but of irregular size (Figure 2). Paired respiratory areas present on alae of car-apace. Smaller respiratory area situated entirely anterior to the larger pair. Anterior pair round, posterior pair kidney-shaped. Antennule (Figure 3) consisting of two parts: stout chiti-nized proximal part bearing hooks and slender distal part. Proximal part bearing a blunt, non-recurving anterior spine, large hook-like terminal spine as well as large recurving medial spine. Distal tubular section extending beyond termi-nal spine and consisting of two podomeres each bearing setae distally. Posterior spine of antennule with large posteriorly directed hook. Antennae four-segmented, basal segment bear-ing posterior spine as well as two tufts of setae, each arranged on rounded protuberance. Remaining three podomeres tubu-lar, each bearing setae apically. Post-antennal spine huge. Maxillulae forming suckers, sclerites differing in number, anterior border with 6-9, posterior with 5-<i, inner with 5-7 and outer with 8-10 (Figure 4). Fringe of setae present around border of sucker rim whilst inner margin supported by short chitinized bars. Row of small, evenly distributed spines present inside sucker rim. Retractile pre-oral spine and mouth tube present between the maxillulae (Figures 2 & 5). Pre-oral spine slender, basally covered by 3-5 large, round scales. Mouth tube somewhat wider, basally with scattered, simple, small scales. Upper lip with deep sinus to expose so-called 'labial' spines that are in fact situated on the tongue. Lower lip cresentic. Two sickle-shaped mandibles visible in cleared specimens. Maxillae five-segmented (Figure 6). Basal segment with postantennal spine S. Mr. J Zool. 1995,30(4) basal plate covered by simple scales, three blunt, evenly spaced spines, and long antero-Iateral process. Second podomere simple, tubular with scales distally. Two types of scales distinguishable, simple comb-like and hand-shaped scales, in a variety of complexities (Figure 6). Third podomere with club-shaped protrusion apically. Protrusion covered by small sharp scales, central part of podomere with hand-shaped scales. Fourth podomere with elevation covered by blunt simple scales. Fifth padomere lacking scales and ter-minating in fleshy lobe and two claws. Pair of accessory spines located between maxillae (Figures 2 & 6) and pair of thoracic spines posterior to maxillae (Fi-gure 2). Four pairs of swimming legs of near equal size on each thoracic segment. Sympods of each leg consisting of two podomeres, endo- and exopodites on all legs. Exopodites on legs 3 and 4 consisting of two parts. Endo- and exopodites bearing two rows of plumose setae each. No flagella present. Natatory lobes on fourth legs consisting oftwo bulbous lobes. with few setae. Area between legs covered by minute simple/pectinate scales (Figure 2). Similar scales also present on the anterior surface of the coxopodites ofleg 1 and leg 4. Adult male. Total length 3,9 mm. Carapace comprising 59% of total body length, sinus in carapace extending along 25% of carapace length. Abdomen comprises 34% of total length: anal sinus differing in shape from that of females and shorter i.e. 45% of length of abdomen. Paired testes with elongated sperm cells visible inside, arranged parallel to lateral walls of testes. Abdomen covered ventrally with spines similar to those on thorax. Accessory sexual structures present on second to fourth Jlijjj)llJJlJljjF 100",", Figure J--6 Argulus smalei n.sp. female and male. Figure 3 antennule and antenna; Figure 4 sclerite rows on different areas ofmaxillule; Fig-ure 5 mouth tube and retractile pre-oral spine; Figure 6 maxilla. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2009).S. Afr. J. Zool. 1995,30(4) 199 Figure 7-8 Argulus smalei n.sp. male. Figure 7 ventral view~ Figure 8 ventral view of basipodite of legs 2, 3 and 4 to show accessory sexual structures. legs (Figure 8). On posterior face of second leg flat disc cov-ered by pectinate scales present. Two bulbous and flag-like protrusions covered by scales present on anterior face of third leg, and cup-shaped socket present on the posterior face. Directly underneath socket copulatory peg present on anterior surface ofbasipodite of fourth leg. Peg divided into two equal bulbous structures. Two smaller protrusions present proximal to peg. Cushion-shaped structure present on posterior face. Natatory lobe reduced to small round protrusion. Spherical, fleshy structure with dimpled surface attached to thorax ventral to gonopore (Figure 8). Remarks The A. smalei male resembles those of A. arcassonensis Cuenot, 1912 in that it possesses a round, dimpled structure ventral to the gonopore, but the species is unique in the shape of the antennae, antennulae as well as the maxillae. In addi-tion huge scales are present on the mouth tube and much smaller scales on the pre-oral spine. Another unique feature is the presence of spines inside the sucker rim of the maxillule. This discovery of A. smalei at Algoa Bay represents the first marine Argulus from the Cape Province, as the previous three marine species were all collected from Natal. Although A. smalei is the first marine Argulus from the fonner Cape Province, A. capensis Barnard, 1955, a freshwater species, was found further south, approximately 100 krn from the southern end of Africa, at Soetendals Vlei near Bredasdorp. The scanty information available at present indicates that in South Africa no Argulus species infest marine as well as freshwater fishes. This was reported by Rushton-Mellor (1994) for a number of species found further north in Africa. Etymology This species is named after Dr Malcolm Smale of the Port Elizabeth Museum who donated the specimens to us. References AVENANT-OLDEWAGE, A. 1994. A new species of Argulus from Kosi Bay, South Africa and distribution records of the genus. Koedoe 37: 89--95. BARNARD, K.H. 1955. South African parasitic Copepoda. Ann. S Afr. Mus. 41: 223-312. RUSHTON-MELLOR, S.K. 1994. The genus Argulus (Crustacea: Branchiura) in Africa: two new species, A. fryer; and A. gracilis, the previously undescribed male of A. brachypeltis Fryer, and the identity of the male described as A. amblopliles Wilson. Sysl. Parasit. 28: 23-31. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2009).

A new species of Argulus (Crustacea: Branchiura) from a bony fish in Algoa Bay, South Africa

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A new species of Argulus (Crustacea: Branchiura) from a bony fish in Algoa Bay, South Africa

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