Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zmmu.msu.ru/files/images/spec/journals/11_3%20173_175%20Heinrich.pdf Дата изменения: Tue Aug 27 08:33:00 2013 Дата индексирования: Fri Feb 28 01:24:10 2014 Кодировка: Windows-1251 Поисковые слова: п п п п п п п п

Arthropoda Selecta 11 (3): 173175

ї ARTHROPODA SELECTA, 2002

Arietellus acutus a new species of Copepoda (Calanoida: Arietellidae) from the southwestern Indian Ocean Arietellus acutus, новый вид копепод (Calanoida: Arietellidae) из юго-западной части Индийского океана Athea K. Heinrich А.К. Гейнрих
P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow 117851 Russia. Институт океанологии им. П.П. Ширшова РАН Москва 11785I Россия.

KEY WORDS: Arietellus acutus sp.n., Calanoida, south-western Indian Ocean. КЛЮЧЕВЫЕ СЛОВА: Arietellus acutus sp.n., Calanoida, юго-запад Индийского океана. ABSTRACT: Arietellus acutus sp.n. from the southwestern Indian Ocean is described. It is similar to A. setosus Giesbrecht, 1892 and A. minor Wolfenden, 1911 in the body shape. The new species is distinguished from them by the structure of the left P5. It is larger than A. minor. РЕЗЮМЕ: Представлено описание Arietellus acutus sp.n. из юго-западной части Индийского океана. По форме тела он сходен с A. setosus Giesbrecht, 1892 и A. minor Wolfenden, 1911. Новый вид отличается от них строением левой Р5. Он крупнее, чем A. minor. New species of Arietellus was obtained from the plankton, collected with Jsaacs-Kidd trawl in the 17th cruise of R/V Vityaz in the south-western Indian Ocean. Plankton was sampled at station 2714, T-18, 33њ22 S, 43њ50' E, depth 850790 m, sample 850650 m, 16 December 1988. New species Arietellus acutus is described below.
segmented, terminal spines of Exp segment 3 of various length. DESCRIPTION: Adult male. Total length 4 mm. Pr 3.6 times as long as Ur. Cephalosome and first pedigerous somite separate. Frontal part of cephalosome pointed and slightly curving ventrally in lateral view. Body hamped dorsally. Last Pr somite with nearly symmetrical, non-divergent ventrolateral spiniform processes, produced backwards and dorsally. Ur 5-segmented. Caudal rami symmetrical, divergent, longer than wide. Caudal setae brocken. Straightened right A1 nearly reaching end of back Pr process. Left A1 brocken. Mouth parts and P1, P2 as described by Giesbrecht [1892] for Arietellus setosus. Many setae on maxillule, maxilla and maxilliped missing because of damage. P5 coxae and intercoxal sclerite fused. Right P5: coxa and basis incompletely fused; basal seta remarkably elongate; Enp 1-segmented; Exp 3-segrnented; distal two segments incompletely separate; Exp segment 2 with process and bunch of setae on inner distal angle; segment 3 spatulate. Left P5: coxa and basis separate; Enp 2-segmented; Exp 3-segmented; segment 3 with 2 terminal spines; longer spine with swelling at midlength, shorter one slightly bent. Female unknown. COMPARISON. The members of this genus are distinguished by the shape of body and the structure P5. The body shape of new species is similar to Arietellus setosus and A. minor in relatively short anterior point of cephalon, slighty curving ventrally, and in large symmetrical, ventrolateral, spiniform. processes of the last Pr somite, and differs in these characters from the remaining species of the genus. A. acutus is distinguished from A. setosus by non-divergent processes of the last Pr somite and left P5 structure. Its Exp segment 3 with long terminal non-bent spine, having swelling at midlength. In A. setosus this spine has a distinct angular bend and is devoid of swelling [Giesbrecht, 1892; Scott, 1909]. Sarss [1924/1925] figure of A. setosus one can see neither bend,nor swelling of the long terminal spine. The figure of P5 is lacking in details. It was drawn at small magnification. It is not clear to which species this specimen belongs. Description of A. minor was brief and lacking in figures of male [Wolfenden, 1911]. General view and size of female

The following abbreviation are used in the description: A1 antennule; Enp endopod; Exp Exopod; P1P5 legs of first-fifth pairs; Pr prosome; Ur urosome. The morphological terminology is based on Huys and Boxshall [1991].

Arietellus acutus sp.n. Figs 110.
Holotype: Adult male. Damaged. The holotype has been donated to the collection of the Zoological Museum of the Moscow University: Me-1197.

NAME: The specific name refers to the head shape. DIAGNOSIS: Arietellus acutus is similar to A. setosus Giesbrecht, 1892 and A. minor Wolfenden, 1911 in short, slightly curving ventrally frontal point, and spiniform projections of last Pr somite. It differs from A. setosus in left P5 Exp segment 3. Terminal long spine of this segment with swelling at midlength. A. acutus is larger than A. minor. Its P5 End 2-


174

Athea K. Heinrich

1.0

1.0

3

0.1

0.1 0.2

4

5

1

2

0.1

6

0.1

7

0.1

8

9

10

Figs. 110. Arietellus acutus sp.n., male (holotype). 1 dorsal view; 2 left lateral view; 3 cephalon (ventral view); 4 the same (right lateral view); 5 last Pr somite and Ur (left lateral view); 6 caudal rami (dorsal view); 7 P5; 8 P5: left Еxр segment 3; 9 the same (another view); 10 P5: left Enp. Scales in mm. Рис. 110. Arietellus acutus sp.n., самец (голотип). 1 вид со спинной стороны; 2 вид с левой стороны; 3 цефалон, вид с брюшной стороны; 4 то же, вид справа; 5 последний сомит Pr и Ur, вид слева; 6 каудальные ветви, вид со спинной стороны; 7 P5; 8 P5, левый Exp; 9 то же в другом ракурсе; P5, левый Enp. Масштаб в мм.

0.1

0.2


Arietellus acutus, a new species of Calanoida
were presented only. Its Pr shape is similar to A. acutus male. It has been known that males and females of this genus have the same Pr shape, and males are smaller than females. Total length of A. minor female is 3.3 mm. Therefore A. acutus male (4 mm) may be distinguished fromA. minor by larger size. The males differ in structure of P5 also: left Exp last segment of A. acutus with, spines of various length; Enp 2-segmented. According to Wolfenden, A. minor has these spines of nearly equal length, Enp 1-segmented.

175

References
Giesbrecht W. 1892. Systematik und Faunistik der pelagischen Copepoden der Golfes von Neapel und der angrenzenden Meersabschnitte // Fauna und Flora des Golfes von Neapel. Nr.19. S.1831. Huys R., Boxshall G.A. 1991. Copepod evolution. London. 468 p. Sars G.O. 1924/1925. Copйpodes particuliиrement batnypйlagiques provenant des campagnes scientifiques du Prince Albert 1er de Monaco // Rйs. Camp. Sci. Prince Albert 1, Monaco. Vol.69. 1924. Atlas. P.1127. 1925. Теxt. Р. 1408. Scott A. 1909. The Copepoda of the Siboga Expedition. Part 1. Free-swimming, litoral and semi-parasitic Copepoda // Siboga Expeditie, monogr. 29. P.1323. Wolfenden R.N. 1911. Die marinen Copepoden der Deutschen Sьdpolar Expedition 19011903 // Deutsche Sьdpolar Expedition 19011903. Bd.12. Zoologie. Bd.4. H.4. S.183380.