91 THE OF SPANISH RESERVOIRS: ECOLOGICAL, SYSTEMATICAL AND ZOOGEOGRAPHICAL REMARKS

Jordi de Manuel Barrabin Departament d'Ecologia, Universitat de Barcelona. Avd. Diagonal 645,08028 Barcelona. Spain,[email protected]

ABSTRACT

This article covers the data from a 1987/1988 survey of one hundred Spanish reservoirs. From each species brief infor- mation is given, focused mainly on ecology, morphology, zoogeography and distribution both in Spain and within reservoirs. New autoecological information on each species is also established giving conductivity ranges, alkalinity, pH and temperature for each. Original drawings and photographs obtained on both optical and electronic microscopy are shown of the majority of the species found. In total one hundred and ten taxa were identified, belonging to 101 species, representing 20 families: (1): (23); Euchlanidae (1); (1 ): (3): Colurellidae (8); (1 5); Proalidae (2); (1); (5); (7); (5); (1 1); Asplanchnidae (3); (3); Conochiliidae (5): (2); Filiniidae (3); Collothecidae (2); Philodinidae () (I). Thirteen species were new records for the Iberian rotifer fauna: Kerutella ticinensis (Ehrenberg); Lepadella (X.) ustucico- la Hauer; Lecane (M.) copeis Harring & Myers; Lecane tenuiseta Harring: Lecane (M.) tethis Harring & Myers; Proales fal- laciosa Wulfert; annecta Harring & Myers; Notommatu cerberus Hudson & Gosse; copeus Ehrenberg: Resticula nyssu Harring & Myers; vernalis Hauer; Gustropus hyptopus Ehrenberg: Collothecu mutabilis Hudson.

Key Words: Rotifera, plankton, heleoplankton, reservoirs

RESUMEN

Este urticulo proporciona infiirmacicin sobre 10s rotferos hullados en el estudio 1987/88 realizudo sobre cien embalses espafioles. Para cnda especie se da una breve informacicin, ,fundamentalmente sobre aspectos ecoldgicos, morfoldgicos, zoo- geogriificos, asi como de su distribucidn en EspaAa y en los emldses. Se uportu infiirmcicicin a lu autoecokogia de cadu especie (rungos de conductividad, alcalinidad, pH, temperatura). Se proporcionun las ilustraciones originales de la mayor parte de las especies (dibujos i microfotografias con microscupia ciptica o electrcinicu). Se iderzt$icaron ciento diez taxones, correspondientes a 101 especies, representando 20 familias: Epiphunidae (I); Bruchionidae (23);Euchlanidae (I); Mytilinid~e(I); Trichotriidae (3); Colurellidae (8); Lecunidae (15); Proalidae (2); Lindiidae (I); Notommatidae (5); Trichocercidae (7); Gustropodidae (5); Synchaetidae (11); Asplanchnidae (3); Testudinellidae (3): Conochiliidae (5);Hexarthridae (2); Filiniidae (3);Collothecidue (2);Philodinidue (Bdelloidea) (1). Trece especies son nuevas citus pura la fauna ihe'rica de rot4fero.s: Keratella ticinensis (Ehrenherg); Lepadella (X.) astaci- cola Huuer; Lecane (M.) copeis Harring & Myers; Lecane tenuiseta Harring; Lecane (M.) tethis Hurring & Myers; Proales fallaciosa Wulfert; Lindia annecta Harring & Myers; Notommata cerberus Hudson & Gosse; Notommata copeus Ehrenherg; Resticula nyssa Harring & Myers; Trichocerca vernalis Hauer; hyptopus Ehrenberg; Collotheca mutabilis Hudson.

Palabras clave: Rot$eru. plancton, heleoplancton, embalses

INTRODUCTION examined the regional limnology of a country with scarcity of natural lakes. One hundred and three reservoirs were extensive- Rotifers constitute an important part of the fresh- ly studied in 1972-75 (Margalef et al. 1976), and water zooplankton. They are usually unimportant revisited 15 years later (1987-88). Both studies in terms of biomass (Ruttner-Kolisko, 1974), but

Liinnetica 19: 91-167 (2000) 0 Aaociaci6n EspaBoln de Limnologi'a, Madrid. Spain 92 de Manuel, J. play a major role in energy transfer and nutrient brachionidae were reported in De Manuel(1991); cycling (Makarevic & Likens, 1979). Rotifers may communities and assemblages in De Manuel & disperse by means of their resting eggs and their Armengol (1993); relationships of each species biogeography has been subject of intense contro- with with physical, chemical and biological versy (Dumont, 1980, 1983; De Ridder, 1981; variables in De Manuel & Jaume (1993, 1994) Shiel et al., 1989; De Manuel et al. 1992). and a comparison between relationships found in Knowledge of the rotifer fauna of Spain is scarce. the previous study and changes in distribution in Velasco (1991) included 349 taxa but for a tempe- Guiset & De Manuel (1993). rate region, this number seems too low. The most complete review of planktonic rotifers is found in Guiset (1976, 1977a), where the distribution of planktonic rotifers is related to reservoir typology. There is large literature, including identifica- tion keys with abundant information on ecologi- cal and systematical aspects of rotifers from dif- ferent regions of the world. In this sense, Pontin (1978) for the British Islands, Stemberguer (1979) for the Laurentian Great Lakes, Braioni and Gelmini (1983) for Italy, Pourriot & Francez (1986) for France and Koste and Shiel (1987a, 1989a, 1989b, 1990ab, 1991) and Shiel & Koste (1992) for Australia, are all examples of rotifer revisions and systematic compilations on system- atical keys. However, not much autoecological and sinecological information of species is reported in these works. This paper records all rotifer taxa found in a 1987-89 survey of one hundred and three Spanish reservoirs. In spite of the fact that samples were Figure 1. Reservoirs studied: 1 La Sotonera; 2 Yesa; 3 Alloz; 4 collected from plankton, a large number of taxa Urrunaga; 6 Ebro; 7 Aguilar de Campoo: 8 El Porma; 9 Barrios de were typically littoral species, both peryphitic Luna; 10 Mime; 11 Doiras; 12 Arbbn: 13 Forcadas: 14 Ribeira; 15 and heleoplanktonic. Fervenza; 16 Portodemouros; 17 Velle; 18 Belesar; 19 0sPeares; 20 As Conchas; 21 San Esteban; 22 Chandrexa: 23 Bao: 24 Cernadilla: The aim of this paper is to identify and deter- 26 Villalcampo; 27 Ricobayo; 28 Almendra; 29 Aldeadivila; 30 mine the occurrence of planktonic and heleo- Saucelle; 3 1 Linares del Arroyo; 32 Cuerda del Pozo; 33 Tranquera: planktonic rotifers in Spanish reservoirs. For each 34 Mequinenp; 35 Flix; 36 Buendia; 37 Entrepefias; 38 El Vado; 39 taxon a brief bibliographical revision on ecologi- El Atazar; 40 Santillana: 41 San Juan; 42 Burguillo; 43 Santa Teresa; 44 Gabriel y Galan; 45 Borboll6n; 46 Alcintara; 48 cal, systematical and biogeographical aspects is Orellana; 49 ZuJar; 50 Valdecafias; 51 Rosarito; 52 Cazalegas: 53 given first. Following, ranges of some physical Guajaraz; 54 Torch; 55 Pefiarroya; 56 Alarccin; 57 Benaixeve; 58 and chemical variables (conductivity, alkalinity, Loriguilla; 59 Sitjar; 60 El Vell6n; 61 Guadalmena; 62 GuadalCn; 63 pH and temperature) are indicated for localities Tranco de Beas: 64 Rumblar; 65 Jandula; 66 Guadalmellato; 67 La Brefia; 68 Bembezar; 69 Retortillo; 70 Guadarranque; 71 were each species was found. Data on the geo- Guadalteba: 72 Conde de Guadalhorce; 73 Iznajar; 74 Los graphical distribution of the taxa recorded in Bermejales: 75 Cenajo; 76 Talave; 77 Puentes; 78 Amadorio; 79 Spain is also given. The work includes original Boadella; 80 Susqueda; 8 1 El Grado; 82 El Pintado; 83 Aracena; 84 drawings and microscopic photographs of the La Minilla; 85 Cala; 86 Torre del Aguila; 87 Bornos; 88 Guadalcacin; 89 Celemin: 90 Guadalnufio; 91 Sobron; 92 Barasona; majority of taxa. 93 Sta. Anna: 94 Camarasa; 95 Oliana: 96 Sant PonG; 97 Frieira; 98 Other investigations on rotifers deriving from San Romin; 99 Mao (Leboreiro); 100 Riudecanyes; 101 Ciceres this extensive survey may be found elsewhere: (Guadiloba); 102 La Concepci6n; 103 Guadalhorce; 104 Contreras. Rotifers of the Spanish reservoirs 93

STUDY AREA AND METHODS Table 1. Number of species from each family identified in Spanish reservoirs (1987/88). Numero de especies de cudu familiu identifi- cudus en los embulses espurioles 987188). The study of Spanish reservoirs was carried (I out in two extensive surveys. One survey was Families no d’esphcies done between November 1987 and March 1988, approximately the mixing period. The second survey was carried out from July to September F. Epiphanidae 1 1988, when the water column was generally stra- F. Brachionidae 23 tified. Fig. 1 gives the location of each reservoir. F. Euchlanidae 1 Rotifer samples were collected with a Nytal E Mytilinidae 1 plankton net 40 pm mesh size. Two replicate F. Trichotriidae 3 samples were taken from each reservoir. Each F. Colurellidae 8 sample was taken as a vertical haul from 20 m F. Lecanidae 15 E Proalidae 2 deep to the surface in the deepest part of the E Lindiidae 1 reservoir. A qualitative sample was also taken as F. Notommatidae 5 an horizontal haul 1-3 m deep while navigating F. Trichocercidae 7 softly about 2 minutes. Samples were anaes- E Gastropodidae 5 thetized with carbonated water and progressive- E Synchaetidae 11 F. Asplanchnidae 3 ly preserved with formaldehyde to reach a 4% F. Testudi nellidae 3 solution in water. A series of measurements of F. Conochiliidae 5 physical, chemical and biological variables were E Hexarthridae 2 carried out in situ. Detailed information on me- F. Filiniidae 3 thods from limnological investigations conduc- F. Collothecaceae 2 ted in Spanish reservoirs can be found in Digonon f Li Margalef et al., (1976); Armengol et al., (1990) EPhilodinidae 1 and Riera et al., 1992. The work of the European rotifer fauna of Voigt (1957) and revised by Koste (1978) has been widely used as a general guide for identifi- cation. However, some reviews and monographs on particular genera and families have been used ROTIFERS OF THE RESERVOIRS. too: Ahlstrom (1940, 1943) and Koste & Shiel ECOLOGIC, SYSTEMATIC AND (19874 for genera Brachionus and Keratella; ZOOGEOGRAPHICAL ASPECTS Stemberger (1 979) for species and Harring (1916) and Harring & Myers (1916, The 1987/1988 survey of Spanish reservoirs have 1922, 1926) and Koste & Shiel (1990a) for ge- been identified 110 rotifer taxa, corresponding to nera Lepudella, Lecane and . 101 species (Table 2) and representing 20 fami- Mastax analyse were carried out in some taxa lies (Table 1). Thirty five of these taxa were for taxonomic identifications. Some specimens euplanktonic species while and the others were (or part of them) were drawn with a camera mainly heleoplanktonic. Thirteen species are new lucida and, occasionally, photographed. Scann- records for the rotifer fauna of Spain. Occurrence ing electron microscopy (SEM) was used for and abundance of each species in reservoirs is distinguishing details of loricated rotifers, and given in De Manuel (1997). was especially useful for the family Rotifers are organized here by families, Brachionidae. Preparation of specimens for ordered according traditional criteria of Remane SEM observation was made following Ansellem (1929-1933), and later modified by Koste (1978). & Clement (1981). Species in each family are ordered alphabetically. 94 de Manuel, J.

Tabla 2. Planktonic and heleoplanktonic species, grouped by families, found in 101 studied Spanish reservoirs (1987-88). * new records for Spain. Especies pluncto'nicas y heleoplanctonicas, agrupadas por familias, que han sido halladas en 10s 101 embalses estudiados (1987-88). * nuevas citas para Espafia.

(Monogononta) L. (X.) astacicolu * F. Synchaetidae olichoptera 0. Ploimida F. Lecanidae I? eurypteru E Epiphanidae Lecane (M.) bulla l? major sentu L. (M.) closterocerca l? remata L. (M.) copeis * l? vulgaris F. Brachionidae L. crepida hudsoni Anurueopsis fissu L. fzexilis l? truncatum Brachionus angularis L. (M.) hamata Synchaeta kitina B. bidentata L. hastata S. oblongu B. budapestinensis L. inermis S. pectinata B. calyciflorus L. luna s. stylata B. falcatus L. (M.) lunaris B. leydigi L. miru E Asplanchnidae B. plicatilis L. (M.) scutata brightwelli B. quudridentatus L. (M.) stenroosi A. girodi B. urceolaris L. tenuiseta * A. priodonta Keratella cochleuris L. (M.) tethis * K. irregularis Gnesiotrocha K. quadrata F. Proalidae S. 0. K. testudo Proales fullaciosa * E Testudinellidae K. ticinensis * sulcata F. Lindiidae K. tropica patinu K. serrulata Lindia annecta * 7: emarginulu K. valga Kellicottia longispinu E Notommatidae F. Conochiliidae Notholca acuminata Cephulodella ,forficulu coenobusis N. labis C. gibba C. dossuarius N. squamula Notommatu cerberus * C. hippocrepis Platyias quadricornis N. copeus * C. nutans Resticula nyssa * C. unicornis F. Euchlanidae dilatutu F. Trichocercidae Trichocerca cylindrica F. Hexarthridae Hexarthra fennica F. Mytilinidae 7: porcellus sulpina 7: pusillu H. mira 7: rcrusseletti E Trichotriidae 7: similis F. Filinidae pocillum 7: .stylatu longiseta 7: tetractis 7: vernalis * F: opoliensis spinifera F: terminalis E Gastropodidae E Colurellidae ecuudis S.0. Collothecaceae Colurella adriatica A. ovalis F. Collothecidae C. colurus A. sultans Collotheca mutabilis * C. uncinata Gastropus hyptopus * C. pelagica Lepadella ucuminatu G. sfylifer L. patella (Digononta) L. ovalis 0. Bdelloidea L. rhomboides F. Philodinidae Rotariu neptunia Rotifers of the Spanish reservoirs 95

Table 3. Number of reservoirs and inventories where species of the genus Polyarrhru occurred in the survey 1987/88. Nuinrro de rmhulsrs .v mursfrus en 10s que se ha encontrudo especies del g6nnrro Polyarthra en el rstudio de 1987/88.

Polyurthra species Number of Number of' Number of' stratified reservoirs mixed reservoirs inventories

E! dolichoptera 16 31 47 I? euvptera 9 7 16 P: mujor 54 45 99 P. rernatu 31 31 62 P. vulgaris 75 68 I43 P. eurqpteru / P. remutu 4 2 6 P: eqptera / P: vulgaris 7 4 11 P. eurqpteru /I? major 4 4 8 P. eurypteru /I? dolichopteru 2 1 3 P vulguris / P: dolichopteru 13 16 29 P: vulgaris / P. remuta 22 20 42 P: mujor / P: dolichopteru 5 14 19 P. major / P. vulguris 41 26 67 P: mujor / P. remutu 15 14 29 P. dolichopteru /I? remuta 5 II 15

Family EPZPHANZDAE Distribution in reservoirs. Rare. In last survey Genus Epiphanes Ehrenberg it was only present in winter samples from (Some literature includes this genus in the Ricobayo reservoir (27). family Brachionidae) Epiphanes senta (Muller, 1773) Family BRACHZONZDAE Vorticella senta Miiller, 1773; Hydutina senta Genus Anuraeopsis Lauterborn Ehrenberg, 1830; Epiphanes senta (Miiller) after Harring, 191 3. Anuraeopsisfissa (Gosse, 185 1) Ecology. Species are mainly heleoplanktonic, Anuraea fissa Gosse, 1 85 1; Anuraeopsis ,fissu but can be found occasionally in plankton sam- Gosse, 1886. ples. Preferentially in small waterbodies, rare in Ecology. Planktonic rotifer, warm lakes and reservoirs. More common in eutrophic estenoterm. Termophil from eutrophic environ- water, it tolerates salinity (Ruttner-Kolisko, ments (Margalef, 1947, 1955). More frequent in 1974). Resting eggs may resist long periods of small waterbodies. Feeds on bacteria and detri- drought, and their presence is possible in tempo- tus (Pourriot, 1977). Anuraeopsis fissu may rary waters. Some flagellate alga as Phacus and appear in the stomache contents of Asplanchna Euglena, are frequent components of its diet (Guiset, 1977~). (Pourriot, 196.5, 1977). Cond: 183.4-351.3 pS cm-'; Alk: 1297.2-1652 Cond: 206.3 pS cm-'; Alk: 1767 peq 1.'; pH: peq 1.'; pH: 8-9.16; Temp: 23-25.5 OC 7.52; Temp: 9.87 "C Morphological features of interest. The species Morphologica1,features [$interest. Present two is polymorphic in shape and size (Berzins, 1962). coulorless eyes. Uncus with six teeth and a very It does not present foot nor caudal spines as other characteristic fulcrum, short and flat. Resting brachionids. Asexual eggs present a short pecu- eggs completely covered by abundant short seta. liar protuberance where the is subjected Geographicul distribution. Cosmopolite. In with the Weber organ (difficult to observe in con- Spain is only found occasionally. tracted individuals).

Rotifers of the Spanish reservoirs 97

Geographical distribution. Cosmopolite. It is the predator rotifer Asplanchna brightwelli. It common in the whole of the Iberian peninsula. feeds on Polytorna, Chlorella and Clzlamidomo- Distribution in reservoirs. In last survey this nas (Braioni & Gelmini, 1983). species was found in plankton samples from Cond: 262-300 pS cm-'; Alk: 2103-2213 peq I-'; only four southern reservoirs, but in the 1972175 pH: 7.5-7.8; Temp: 7.7-10.8 "C survey it was collected in 28 samples from 18 Morphological features qf interest. It may be localities. distinguished by the presence of lateral spines that are longer than the rest of spines. It is one of Genus Brachionus (Pallas) the most polimorphyc species and several morphs have been described (B. b. f inermis; B. b. f cras- Brachionus angularis (Gosse, 195 I) (Fig. 2) (Fig sispeineus; B. b. .f testudinarius; B. b. fjirovci; B. 38) b. f minor). Brachionus angularis angularis Koste, 1978. Geographical distribution. Cosmopolite. In Ecology. Planktonic species, common in Spain it has been recorded only occasionally. The superficial water. It can also be found in the lit- morph B. b. f inermis (Rousselet, 1906) has fre- toral zone, among macrophytes. Euriterm, euri- quently been found in littoral ponds from haline and perennial. It presents its maximum in Cartagena (unpublished data from the author). B. spring and autumn. It feeds on bacteria and detri- b. 5 testudinarius (Jakubsky, 19 12) has not been tus (Boon & Shiel, 1990), as well as on some found in the Iberian peninsula, but was collected algae groups (Pourriot, 1977) such as chlorococ- in turbid temporary ponds from Menorca and cales, volvocales, euglenales and central diatoms. Mallorca (De Manuel et al., 1992). Cond: 169-3720 pS cm-'; Alk: 1157.2-3038 Distribution in reservoirs. In last survey pre- peq 1.'; pH: 7.7-9; Temp: 10.2-26.1 "C sence was first detected in mainland reservoirs. Morphological features of interest. It presents The morph B. b. f: crassispineus (Hauer, 1963) a great variability in size and shape. The dorsal has been found in 3 reservoirs: Villalcampo (26), plate of the lorica is considerably variable. Eggs Aldeadhvila (29) and Saucelle (30). are carried joined to the opening of the foot. Geographical distribution. Cosmopolite. In Brachionus budupestinensis Daday, 1 885 (Fig. 2) Spain it has been found in numerous and wide- (Fig. 33) spread localities. ArCvalo (1918, 1923) and Brachionus lineatus Skorikov, 1896; Brachio- Margalef (1948a) reported the presence of the nus punctatus Hempel 1896; Brachionus similis taxon B. angularis fi bidens (Plate, 1886), cha- Leissing 1914. racterized by the form of the lorica in the opening Ecology. Species associared to high pH waters. of the foot. Warm stenoterm. It tolerates moderate saline con- Distribution in reservoirs. In the most recent ditions. This species may be found in runing survey it has been found in six reservoirs (in 5 waters. during the stratification period and in 1 during the Cond: 541 pS cm-'; Alk: 3038 peq 1.'; pH: 8.1; mixing period). It was specially abundant in Temp: 24.3 OC GuadalCn (62). Morphological .features of interest. Lorica without caudal spines. Ornamentation and varia- Brachionus bidentata (Anderson, 1889) (Fig. ble disposition of dorsal facets. Its size is very 2)(Fig. 3, k) constant. Brachionus bidentatus Kertesz, 1894; Geographical distribution. Cosmopolite. More Brachionus furculatus Thorpe, 1891. commonly found in tropical and subtropical r Ecology. Planktonic species, prefers small regions. In the Iberian peninsula it has previous- waterbodies. Pourriot (1974) describes the elon- ly been found by Guisande & Toja (I 988) in the gation of the spines induced by the presence of estuary of the river Guadalquivir. It has also been 98 de Manuel. J collected in samples from small waterbodies near Brachionus falcatus Zacharias 1898 (Fig. the coast of Cartagena (unpublished data from the 2)(Fig. 3,i) author). Ecology. Planktonic species, termophilus. Distribution in reservoirs. Its presence in Autoecology is largely inknow. Villalcampo (26) is first reported in this study. Cond: 48-1423.5 pS cm-'; Alk:266-2002 peq 1-l; pH: 8.1-8.6; Temp: 23.6-25.5 "C Brachionus calyciflorus Pallas 1766 (Fig. 2) Morphological features of interest. It presents (Fig. 3,d-g) six spines on the anterior dorsal margin. Brachionus pala Ehremberg, 1838. Intermedial spines detach by their length. Body Ecology. Planktonic species; common. ended by two long caudal spines, widely separa- Occasional in runing water. Euritherm in ted at their base. Relatively low variability in size eutrophic water. Often abundant in small and shape, with spines always well developed. eutrophic waterbodies. Very tolerant of high Geographical distribution. Pantropical and chloride concentrations. Filtrer-feeding, it feeds pansubtropical. Widely distributed in subtropical on bacteria and detritus, chlorococcales, volvo- regions, especially in South-America. De Ridder cales and euglenales (Pourriot, 1977). (198 1) contends that this species is clearly in geo- Cond: 22-3720 pS cm-'; Alk: 131-3667 peq 1.'; graphical expansion. In the Iberian Peninsula it pH: 6.6-9. I; Temp: 7.7-26.1 "C has been found occasionally (Monteiro, 1984; Morphological features of interest. Soft, sack- Guisande & Toja,1988). It has been found in a shaped lorica, with four anterior spines. Very small waterbody in Extremadura ("charca de polymorphic species in shape and size. Some Berrueco", unpublished data from the author). morphotypes have been described: Distribution in reservoirs. An abundant popu- B. c. 5 dorcas (Gosse) (Fig 3, g) with a round- lation was found in summer samples from Bornos ed posterior margin of the lorica and medial ante- (87). Some specimens were collected in La rior spines longer than lateral spines. Minilla (84) and Borboll6n (45). B. c. 6 amphiceros (Ehrenberg) (Fig 3, d-f) with postero-lateral spines of variable size. It pre- Brachionus leydigi Cohn, 1862 (Fig. 2)(Fig. sents spines on the opening of the foot. 3,h) The taxonomic value of these morphs are dis- Brachionus quadratus val: tridentatus (Zer- cussed, as some variability may be phenotypic nov, 1901). and brought about by environmental factors. Ecology. Heleoplanktonic species, cold Gilbert (1967) found a positive influence on the stenoterm. More frequent in small waterbodies, it development of posterior spines in the presence tolerates relatively high salinity. of the predator Asplanchna, interpreting the lar- Cond: 262 pS cm-'; Alk: 2103 peq 1.'; pH: 7.5; ger spines as a mechanism for mechanical Temp: 7.7 "C defense. Posteriorly, Stemberger (1990) found an Morphological features of interest. The basal important relationship between the size of spines, plate of the lorica presents a distinctive medial the size of the lorica and the presence of crest. The most characteristic feature of this Asplanchna and available food. species is the presence of three spines on the Geographical distribution. Cosmopolite. It is opening of the foot. Resting eggs with short and widespread throughout all the Iberian peninsula. wide spines. B. leydigi is very polymorphic, Distribution in reservoirs. In the recent study it Ahlstrom (1940) remarks the variability of the has been found in 17 reservoirs, 13 in the stratifi- foot opening, as well as the morphology of the cation period and seven after mixing. In the pre- three spines. vious study the species had been found in 28 Geographical distribution. Cosmopolite. In reservoirs, preferentially in the basins of river the Iberian peninsula it has been recorded in the Duero and river Tajo. estuary of the river Guadalquivir (Guisande &

Rotifers of the Spanish reservoirs 101 known (Walker, 1981). It is relatively easy to cul- B. f. cluniorbicularis (Skorikov, 1894) and B. ture and in the last decades it has acquired great f. brevispinus (Ehrenberg, 1832) have been col- importance for aquiculture and research. It is lected in seven reservoirs located in the north- importance has been extended fields as genetics ern area of the Iberian peninsula and only dur- and evolution (King & Snell, 1977: Snell & ing the summer (Fig. 4). Hawkinson, 1983; King, 1989; among others). Cond: 1423-3720 pS cm-I: Alk:1455-1927 peq 1- Brachionus urceolaris Muller, 1773 (Fig. 3,m) I; pH: 8.2-8.5; Temp: 19.3-26 "C Tubipora urceus Linnaeus, 1758; Brachionus Morphological features of interest. The lorica nicaraguensis, Schmarda, 1 859: Brachionus is relatively soft and flexible. The species is cha- pyriformis, Barrois & Daday, 1894. racterized by the presence of four lobules in the Ecology. Mainly heleoplanktonic species, anterior ventral plate. It presents a notable sexual common in alkaline small waterbodies. dimorphism. There are many morphotypes of this Eurihaline, it tolerates relatively high salinity. It species (Sudzuki, 1987; Koste 1980b). has been found in current waters. Geographical distribution. Cosmopolite. In Cond: 161.5-541 pS cm-I; Alk 618-3038 peq 1-I; Iberian peninsula it has been collected in coastal pH: 7.25-9; Temp: 7.35-24.3 "C ponds and endorheic ponds with high or modera- Morphological features of interest. Dorsal te salinity. Serra & Miracle (1983) and Serra anterior spines above a small basis. It presents (I 987) have studied the variability of this species an approximately rectangular dorsal opening of across a range of environments found in the the foot. Ventral opening with semicircular Iberian peninsula. shape. As other species of the genus, it has a Distribution in reservoirs. It has been found in great plasticity and presents abundant morphs summer samples from three southern reservoirs: and variability of size. Puentes (77), Torre del Aguila (86) and Bornos Geographical distribution. Cosmopolite. It has (87). It was not found in previous surveys. been collected throughout the Iberian peninsula. Distribution in reservoirs. It has been identi- Brachionus quadridentatus Hermann, 1783 (Fig. fied in six reservoirs (Fig. 4), €ive belonging to 3,a-c) the basin of the river Duero, preferentially during Brachionus capsuliflorus Pallas, 1766; the mixing period. The distribution of this species Brachionus bakeri Muller, 1786. Brachionus bre- found here is very similar to the distribution vispinus Ehrenberg, 1832; Brachionus clunior- found in the previous study. bicitlaris Skorikov, 1894. Ecology. Heloplanktonic species. Common in Genus Keratella Bory de St. Vincent small waterbodies and also in current waters. It prefers alkaline water. Eurihaline, it may live in Keratella cochlearis (Gosse, 1851) (Fig. 5 a-f') moderate saline water. (Fig. 6 b) Cond: 197.2-765.5 pS cm-': Alk: 1679-3545.5 Anuraea cochlearis Gosse, 185 1: Anuraea peq 1-l; pH: 8.1-9.1: Temp: 16.3-24 "C longispina Imhof, 1883; Anuraea intermedia, Morphological features of interest. The lorica Imhof, 1885. normally ends in the posterior part in two lateral Ecology. Euplanktonic species. Very common spines of variable length. It is a very variable in lakes and reservoirs, but uncommon in small species, Its posterior spines have negative allo- waterbodies. Eurithermic, it tolerates a wide metric growth. range of mineralization. It feeds on a great varie- Geographical distribution. Cosmopolite, it is ty of algae as well as organic detritus and bacte- maybe the most common species of the genus ria (Pourriot, 1965, 1977; Boon & Shiel, 1990). It Brachionus. is one of the most abundant prey found in the Distribution in reservoirs. Only the morphs stomach of Asplanchna and Ploesoma (Guiset, 102 de Manuel, J.

1977~).Some variables as temperature, food Distribution in reservoirs. It is found in most availability, as well the presence of predators, Spanish reservoirs. It is more frequent and abun- determine different morphs (Stemberguer & dant during the stratification period. K. var: his- Gilbert, 1984), sometimes described as separate pida, (Fig. 4. f) has been found in Urrunaga (4), species. It also presents seasonal variations in and it is the first record of this taxon in Spain. morphology. (f typica) Cond: 14.7- 5326 pS cm-I; Alk: 58- Keratella irregularis (Muller, 1786) (Fig. 5 g-i 4681 peq 1-I; pH: 6.3-10.1; Temp: 6-26.7 OC and Fig 6 c) (f tecta) Cond: 22-5326 yS cm-I; Alk: 131- Anuraea cochlearis var: irregularis Lauter- 3882 peq 1.’; pH: 6.6-10.2; Temp: 6-26.7 “C born, 1898. Morphological features of interest. It presents Some autrors (Carlin, 1943; Ruttner-Kolisko, polymorphism in the size of the lorica and in the 1974; Koste, 1978) considers it as a variety of K. length of the caudal spine. Numerous varieties cochlearis. Ahlstrom (1945), Kutikova (1970) have been described, but controversy exists about and Pejler (1977), among others, relates it as K. the phenotypic or genotypic origin of differences. irregularis, with species category. The distinction among morphs is based on the Ecology. Euplanktonic species. Warm length of the caudal spine and on the size of the stenoterm. It is highly seasonal, occurring in late lorica: spring, with a maximum in summer and a fall in K. cochlearis $ rnacracantha (Lauterborn, abundance in early autumn. 1898) (Fig. 5 a), with a long caudal spine (80 - Cond: 19.6-808 pS cm-l; Alk: 116.8-3545.5 110 pm). peq 1.’; pH: 7-9.9; Temp: 15.9-24.8 “C K. cochlearis$ tecta (Gosse, 1851) (Fig. 5 e). Morphological features of interest. Very similar Spineless morph. It constitutes the most smallest to K. cochlearis. Differences should be found in morph of the series. Koste & Shiel (1987b) con- the dorsal morphology of the lorica. The distinc- sidered this taxon as species (based on the first tive character is the presence of a small medial description of Anuraea tecta,Gosse, 185 1). plaque of pentagonal shape, slightly in the right, K. cochlearis f micracantha (Lauterborn, between carinal plaques (Fig. 6 c). Nipkow (1961) 1900) (Fig 5 c,d). Characterized by a shorter also found differences between the size and shape spine than the typica morph. It is an intermediate of resting eggs of K. cochlearis and K. irregularis. stadium between the typical form and the spine- Geographical distribution. Cosmopolite. less one. Probably it has frequently been confused with K. K. cochlearis var: hispida (Lauterborn, 1898) cochlearis. For this reason, K. irregularis is not (Fig. 5 f), with a wider lorica than the tipica recorded in the checklist of Velasco (1990). morph, it is covered by small protuberances Distribution in reservoirs. It follows a latitudi- (“hair”), contrasting with the areolated ornamen- nal distribution. It is present in summer samples tation of other taxa of the series. The caudal spine in northern reservoirs (Fig. 9). In the last study it is relatively short (Koste & Shiel, 1987b, confers has been identified during the stratified period in it species category). approximately 25% of reservoirs. In the previous K. cochlearis var: robusta (Lauterborn, 1900). study it was also found in summer, in 9% of (Fig. 5 b). Lorica bigger than the typica morph. Spanish reservoirs, as well in northern regions. The caudal spine is generally long. Geographical distribution. Cosmopolite. It is Keratella quadrata (Muller, 1786) (Fig. 7 a,b) probably the most common rotifer and is wide- Brachionus quadratus Muller, 1786; Anuraea spread throughout the world (Ahlstrom, 1943). It aculeata Erhenberg, 1832; Keratella quadrata is found across the whole Iberian peninsula, but after Bory de St. Vincent, 1822. its presence has not been detected in the Balearic Ecology. Euplanktonic species. Perennial, it is archipelago (De Manuel et al., 1992). not seasonal. It has a wide range of tolerance to

106 de Manuel. J mineralization and temperature. Poliphagous, it procurva (Thorpe, 1891), which is smaller and feeds on organic detritus and bacteria, chlorococ- with a lorica not robust. The latter species inha- cales, volvocales, euglenales, chrysophyceae and bits more alkaline waters. central diatoms (Pourriot, 1977). Geographical distribution. Cosmopolite. It is Cond: 19.6-5326.6 pS cm-'; Alk: 98-4681.7 not found in tropical regions. In the Iberian peq 1.'; pH: 6.64-10.18 ; Temp: 6.4-26.1 "C peninsula it has been collected in NW reservoirs Morphological features of interest. Lorica (Margalef, 1955). generally almost rectangular; posteromedial Distribution in reservoirs. It has been found in plaque is hexagonal. Two caudal spines inserted reservoirs from Galicia, NW. Spain (Fig. 9). It at posterolateral corners of the lorica. Extremely has also been collected in a recent study in Mao polymorphic in size and also in the length of the (99), a reservoir characterized by a low conduc- caudal spines. Lorica surface with strong granu- tivity (1 9.75 mS cm-2)and relatively acid pH (i.e. lation. Mictic females, which produce resting 6.83) and in Ribeira (14). eggs, usually present longer caudal spines, which are progressively reduced in successive genera- Keratella testudo (Ehrenberg, 1832) (Fig. 7 c) tions (Ahlstrom, 1943). K. quadrata presents an Anuraea testudo Ehrenberg, 1832; Anuraea alometric relationship between the caudal spines aculeata brevispina Weber, 1898; Anuraea bre- and the lorica (Margalef, 1948a; Pejler, 1962; vispina, Gosse, 185 1; Keratella quadrata bre- Miracle, 1976; Guiset, 1977b). vispina, Edmondson & Hutchinson, 1934. Geographical distribution. Cosmopolite. Ecology. Planktonic species. Mostly in small wa- Widely distributed across the Iberian peninsula. terbodies. According Sladecek (1983) it feeds on Distribution in reservoirs. Very common in bacteria, organic detritus, chlorococals, euglenales, reservoirs (72%), but generally with not very cryptomonadaceae, chrysophyceae and diatoms. abundant populations. Cond: 50-81 pS cm-'; Alk: 242-447.6 peq 1-l; pH: 7.15-7.2; Temp: 10.2-18.9 OC Keratella serrulata (Ehrenberg, 1838) (Fig. 7 f> Morphological features of interest. Trapezoidal (Fig. 8 a) lorica with a rounded posterior margin. Posterior Anuraea serrulata Ehrenberg, 1838; Keratella spines very short, asymmetric and slightly diver- falculata Ehrenberg, 1838; Keratella serrulata gent. The left-poster0 spine may be shorter than after Harring, 1913. the right spine. It may be confused with the species Ecology. According to Berzins & Pejler K. quadrata, which has not two completely closed (1987), it is the only planktonic brachionidae spe- lateral facets, as K. testudo has (Fig. 8 b). cialist from acid waters. Common in acid water Geographical distribution. Cosmopolite. It is a from bogs with Sphagnum. It feeds on chryso- rare species, occurring occasionally. In the phyceae and volvocales (Pourriot, 1977). Iberian peninsula it was first found by Cond: 22 pS cm-'; Alk: 131 peq 1.'; pH: 6.6; Wizniewski (193 1) and ArCvalo (1932); Fores et Temp: 18.6"C al. (1986) collected it in ponds of Delta de l'Ebre, Morphological features of interest. Robust lo- in the NW Spanish mediterranean coast. rica, granulated or covered by short spines or Distribution in reservoirs. In this survey it has granules. Anterior spines on margins are slightly been found in Frieira (97), in winter samples, in serrated (Fig. 8.a). Posterior lateral corners of lo- low abundance. In the previous study of reser- rica with spines of variable length or spineless. voirs it was collected from Susqueda (80) and Systematic diagnosis of the species is on the Aldeadhvila (29). absence of the posteromedial plaque and the pre- sence of a median line separating posterocarinal Keratella ticinensis (Ehrenberg, 1834) (Fig. 7 i) plaques. K. serrulata may be confused, by dispo- Anuraea curvicornis Ehrenberg, 1834; sition of its plaques, with the species Keratella Anuraea aculeata var: ticinensis Callerio, 1920.

108 de Manuel, J. Ecology. Species from ephemeral and dys- southern territories of the Iberian Peninsula, but trophic waterbodies (Koste, 1978). Heleoplank- occasionally also in northern waterbodies. tonic. Ruttner-Kolisko (1974) sustained that K. Distribution in reservoirs. It was collected in ticinensis is a transition species between quadra- only eight reservoirs in the 72/75 survey, but in ta and serrulata groups. last study it has spread its distribution to 17 Cond: 77 pS cm"; Alk: 429.2 peq 1-l; pH: 7.1; localities (Fig. 9). Temp: 9.6 OC Morphological features of interest. Oval lorica, Keratella valga (Muller, 1786) (Fig. 7 d,e) rounded and spineless posterior end. Anterior Anuraea valga Ehrenberg, 1834; Keratella spines are relatively long. It may present small valga after Ahlstrom, 1943. There is controversy protuberances in the dorsal part of the lorica. about the specific definition of K. valga and K. Anteromedial plaque is approximately squared tropica. Alhstrom (1943) considered K. tropica as and is a diagnostic trait. May be confused with a morph of K. valga, Ruttner-Kolisko (1974) spineless morphs of K. cochlearis (K. c. J: tecta, included K. valga as a morphotype of K. quadra- Fig. 4. e), but K. ticinensis is bigger, and the ta. Recently, the tendency is to consider both taxa disposition of dorsal plaques is very distinctive. Its as separate species. eggs are covered by short spines with curved ends. Ecology. Planktonic species, euriterm. Inhabits Geographical distribution. It is considered as a small waterbodies with low alkalinity. Feeds cosmopolite species, but its actual distribution is meanly on cryptomonadaceae and volvocales European. The population found in reservoirs are (Pourriot, 1977). the first record of this species in the Iberian Cond: 51.5-78.3 pS cm-'; Alk: 171-439.3 peq peninsula. 1-l; pH: 6.8-7 ; Temp: 7.8-9.4 "C Distribution in reservoirs. It has been found in Morphological features of interest. Very simi- winter samples in a survey by Frieira (97) in lar to K. tropica. Lorica broader at anterior end. Galiza; (conductivity 77 mS cm-2,pH 7.25). No posteromedial remnant under posteromedial plaque. Caudal spine not very long, unequal in Keratella tropica (Apstein, 1907) (Fig. 7 g,h) length or only one present. Resting eggs with (Fig 8 c) prickly shell. Anuraea valga f. tropica Apstein, 1907. Geographical distribution. It has only been Keratella valga J: tropica after Edmondson and found in the Paleartic region and Australia Hutchinson, 1934. (Pejler, 1977). Uncommon. In the Iberian penin- Ecology. Euplanktonic species. Warm sula it has occasionally been found in small stenoterm, preferentially in alkaline waters. waterbodies (De Ridder, 1962; Arkvalo, 1923) Cond: 262-1065 pS cm-'; Alk: 2103-3486.5 and in some reservoirs. peq I-I; pH: 8.1-8.49; Temp: 18.5-24.5 "C Distribution in reservoirs. In both surveys Morphological features of interest. Rectangular some specimens of K. Valga were occasionally lorica. Posterior spines unequal, with the right found, mainly in NW reservoirs with waters of spine longer than left. The last can be absent even low mineralization. when right spine is quite long. K. tropica has a posteromedian remnant after the postero postero- Genus Kellicottia Ahlstrom medial plaque (Fig. 8 c), sometimes difficult to observe. This remnant is the only feature which Kellicottia longispinu (Kellicott, 1879) (Fig. 11 differences it from K. valga. The lengths of spines a) (Fig. 10) and lorica are very variable, and there is an allo- Anuraea longispinu Kellicott, 1879 metric relationship between them. Ecology. Euplanktonic species. Perennial and Geographical distribution. Pantropical and meanly inhabitant of oligotrophic lakes. It is not pansubtropical. It has frequently been found in found in small waterbodies. According to

112 de Manuel, J.

Genus Notholca Gosse Ecology. Planktonic species, but frequently found in littoral environments. It tolerates a wide Notholca acuminata (Ehrenberg, 1832) (Fig. 11 range of salinity. Cold stenoterm. It feeds mainly d) (Fig. 10) on diatoms. Anuraea acuminata Ehrenberg, 1832. Cond: 189-1126.3 pS cm-I; Alk: 689.5-4681.7 Ecology. Heleoplanktonic species. Cold peq 1.'; pH: 7.9-8.5; Temp: 8.4-12.3 "C stenoterm. More frequent in littoral benthos than Morphological features of interest. Lorica with in plankton, where it is found occasionally. It feeds rounded caudal margin, finely striated, with six on central and pennal diatoms (Pourriot, 1977). spines on the anterior dorsal margin. The quotient Cond: 293-821 pS cm-I; Alk: 1996-3039.3 lengtwwidth is always less than 2. It presents peq 1.'; pH: 7.69-8.2; Temp: 10.63- 11.57 "C cyclomorphosis and it is frequently larger at low Morphological features of interest. Lorica lon- temperature. gitudinally striated, with six spines on the anteri- Geographical distribution. It is the most com- or margin. It presents a caudal appendix of varia- mon species of the genus and it is widespread ble length. throughout the Iberian Peninsula. In littoral Geographical distribution. It has been found ponds it may be easily confused with N. salina in Europe, North of Africa and Asia Minor. (Focke) Common in the Iberian Peninsula. Distribution in reservoirs. It was found mainly Distribution in reservoirs. In the previous in eutrophic reservoirs with alkaline waters. It study it was collected in eight plankton samples. has been collected in winter samples from eight In this survey it was also found in St. Anna (93) localities of eastern areas of the Iberian Peninsula and in Sitjar (59), in winter samples. (Fig. 10).

Genus Platyias (Harring) Notholca labis Gosse, 1887 (Fig. 11 c) (Fig. 10) Ecology. Heleoplanktonic species. Cold steno- Platyias quadricornis (Ehrenberg, 1 832) term, it may be inhabit considerably saline water. Noteus quadricornis Ehrenberg, 1832; Platyias Cond: 112 pS cm-'; Alk: 779 peq 1.'; pH: 7.53; quadricornis (Ehrenberg) after Harring, 1913. Temp: 9.5 "C Ecology. Heleoplanktonic species. Prefers Morphological features of interest. Lorica warm water and presents tolerance to moderate elongated and oval, striated longitudinally, salinity. It is frequently found among littoral with almost rectangular and spade-shaped cau- macrophytes (Pejler, 1977). dal extensions. Gosse compared its lorica with Cond: 305-765 pS cm-'; Alk: 1194-3065 peq 1-I; the handle of a dust pan (Fig. I1 c). Poly- pH: 8-8.5; Temp: 21 32-22.8 "C morphic. Morphological features of interest. Lorica with Geographical distribution. Probably cosmopo- a pentagonal dorsal facet between two hexagonal lite. Rare. In Spain it has only been found in reser- facets. The species presents variability in the size voirs and in Pyrenean lakes (unpublished data). and length of its caudal spines. Eggs are carried, Distribution in reservoirs. It was found in the like other brachionidae, on the opening of the previous study in Sobron (91). In the 1987/88 foot. study it has been found in a reservoir of the basin Geographical distribution. Cosmopolite, more of the river Tajo, Cazalegas (52) (Fig. lO), in common in tropical and subtropical regions. In samples taken during the mixing period. Spain it has occasionally been found, mainly coastal ponds: Doiiana National Park (De Ridder, Notholca squamula (Muller, 1786) (Fig. 11 b) 1962); Cullera (Miracle & Vicente, 1983); and in (Fig. 10) rice fields of the delta of river Ebre (Fords et al. Brachionus squamula Muller, 1786. 1986). Rotifers of the Spanish reservoirs 113

Distribution in reservoirs. Rare. In the present alkaline waterbodies. It also may be found in dys- study it has been found in plankton samples from trophic environments. Boadella (79) and Flix (35). Cond: 77-3130 pS cm-'; Alk: 429.2-3038 peq 1-'; pH: 7.1-8.1; Temp: 8.6-24.3 OC Fami 1y E UCHLANIDAE Morphological features of interest. Robust Genus Euchlanis Ehrenberg lorica, of triangular section, with the anterior margin always serrated. It presents a dorsal keel Euchlunis dilatata Ehrenberg, I832 with transverse folds mostly over caudal part of Ecology. Heleoplanktonic species. Frequent the lorica. Trophi malleate, with six teeth on among macrophytes in small waterbodies. uncus. Foot ventrally curved, with three joints Tolerates moderate concentrations of salinity and and toes sharply pointed. I may be confused with may occur in fresh and brackish water. It prefers L. oxysternon (Gosse, 185 l), which does not pre- eutrophic water, especially when cyanobacteria sent caudal folds on the dorsal keel. are abundant. Pejler (1 962) remarks it is a species Geographical distribution. Cosmopolite. It is that frequently appears attached to planktonic an uncommon species, but has been found spread algae colonies. According to Carlin (1943), it across the whole Iberian Peninsula territory feeds on organic detritus, bacteria, cyanophicea (unpublished data), in spite of the fact that it has and Cyclotella. been recorded in few localities (Velasco, 1990). Cond: 19.6-823 pS cm-'; Alk: 98-3757 peq 1.'; Distribution in reservoirs. In the 1987188 sur- pH: 6.3-9.6; Temp: 6.4-24 "C vey it was found in seven localities (Fig. 4.12), Morphological features of interest. Ovoid mainly in winter samples (mixing period). body, lorica transparent and flexible. Lorica is truncate at its anterior margin and was a rounded Family TRICHOTRIIDA E posterior end. Posterior dorsal plate is divided by a deep elongate notch. Foot slender and two- Genus Trichotria Bory de St. Vincent jointed. Size is remarkably variable and several specific morphs have been described attending to Trichotriu pocillurn (Miiller, 1776) (Fig. 12 e) the section and shape of the lorica. Trichoda pocillum Miiller, 1776; Dinocharis Geographical distribution. Cosmopolite. It has pocillum Ehrenberg, 1830; Trichotria pocillum, been found all over Spain. Bory de St. Vincent, 1827. Distribution in reservoirs. In the 1987188 sur- Ecology. Periphytic species, heleoplanktonic. vey it was identified in samples, from 19 reser- It feeds on organic detritus and algae, mainly voirs across the whole Iberian Peninsula, both diatoms from phytobenthos. It tolerates a wide from the stratificatin period and after mixing. In range of mineralization. the previous study its occurrence was important Cond: 262-378.5 pS cm-I; Alk: 2103-2987 in spring. peq 1.'; pH: 7.5-8.1; Temp: 7.7-9.1 T Morphological ,features of interest. Robust Family MYTILINIDAE lorica covering head, body and feet, like a Genus Lophocharis Ehrenberg shield of hexagonal section. Lorica ornamented with spicules and organized in regular facets Lophocharis salpina (Ehrenberg, 1834) (Fig. I2 (with similarities with the lorica of some bra- c; Fig. 13) chionids). Trophi malleate. Foot with two long Lepadella salpina Ehrenberg, 1834; Metopidia and slender toes. T pocillum has a small spine salpina Hudson & Gosse, 1889; Lophocharis in the last segment of the foot, just between the salpina after Harring, 19 16. two toes (Fig. 12 e). This trait makes it possible Ecology. Periphytic species, occasionally to distinguish this species from 7: tetractis occurring in plankton. It inhabits preferentially (Ehrenberg, 1830).

118 de Manuel, J.

and C. colurus. Different ecotypes have been fied in Cenajo (75). In the previous survey it was described in relation to the size and shape of the collected in five reservoirs. lorica, as well as length of the foot. Both species increased their size with salinity (Hauer, 1924). Genus Lepadella Bory de St. Vincent Geographical distribution. Probably cosmopo- The genus has been traditionally split into three lite. In Spain it has been found in numerous and subgenera distingued by the morphology of the widespread localities. toes: Lepadella (equal toes; completely separate); Distribution in reservoirs. It has been collected Heterolepadella (unequal toes); Xenolepadella only in Cenajo (75), in summer samples. In the (joined toes; either totaly or parcially). previous survey it was found in five reservoirs. Lepadella acuminata (Ehrenberg, 1834) (Fig. 15 Colurella colurus Ehrenberg, 1830 (Fig. 14 c,d) c; Fig. 16) Monura colurus Ehrenberg, 1830; Colurella Metopidia acuminata Ehrenberg, 1834; colurus after Harring, 1913. Lepadella acuminata after Dujardin, 1841. Ecology. Heleoplanktonic species. Eurihaline. Ecology. Periphytic species, occasionally With similar ecological requirements C. adriatica. found in plankton. According to Koste (1978) it Cond: 77 pS cm-I; Alk: 429.2 peq 1.'; pH: 7.1; prefers slightly acid water. Temp: 9.7 "C Cond: 51.5-304.7 pS cm-'; Alk: 171-2089 Morphological features of interest. Relatively peq 1-I; pH: 6.8-8.3; Temp: 7.8-19 "C smaller than C. adriatica, it may be discriminated Morphological features of interest. Dorsal lo- by the morphology of the posterior margin of the rica with two lateral keels. Lorica ends with an lorica, which is rounded in C. colurus (Fig. 14). acute margin. This character distinguishes this Geographical distribution. Cosmopolite. In species from the other species in the genus. the Iberian peninsula it has been found in fewer Geographical distribution. Cosmopolite. In localities than expected from its know distribu- the Iberian Peninsula it has been found quite a tion (unpublished data). few localities, all with low mineralization. It Distribution in reservoirs. In the previous one of the most common species of this genus in study it was found in seven reservoirs. In the last high mountain lakes; for instance in Sierra survey it was only found in Frieira (97) and only Nevada (Morales-Baquero, 1987), as well as in in winter. Pyrenean mountains (Margalef, 1948b, and unpublished data). Colurella uncinata (Muller, 1773) Distribution in reservoirs. It has been found in Brachionus uncinatus Muller, 1773; Colurella three northern localities, Aguilar de Campoo (7), uncinata after Harring, 1913. As Conxas (20) and Barasona (92), in all of them Ecology. Periphytic species, occasional in in summer samples. In the previous survey it was plankton. It tolerates a wide range of minera- collected in five localities. lization. Cond: 383.7 pS cm-'; Alk: 3349.7 peq 1.'; pH: Lepadella (Xenolepadella) astacicola Hauer, 8.4; Temp: 23.5 "C 1926 (Fig. 15 b; Fig. 16) Morphological features of interest. Lorica with Ecology. Littoral species. It has been described a head-opening smaller than the greatest lorica as inhabitant of the bronchial cavity of the river height. Lorica ends in its posterior end with a crayfish (of the genus Astacus and Cwitharus). downward-curving short spine. Short toes. Cond: 158.3 pS cm-I; Alk: 1099.3 peq I-l; pH: Geographical distribution. Cosmopolite. In 9.19; Temp: 17.7 OC. the Iberian Peninsula it is more common in Eas- Morphological features of interest. Its most tern regions (Velasco, 1990). distinctive character is the complete fusion of Distribution in reservoirs. It has been identi- the toe.

120 de Manuel, J.

Distribution in reservoirs. It has been collected Distribution in reservoirs. Found in summer in San Juan (41) and San Romh (98). In the previ- samples from GuadalCn (62), Retortillo (69) and ous survey it was only found in one reservoir. La Concepci6n (102).

Lepadella patella (Muller, 1786) (Fig. 15 a) Family LECANIDAE Brachionus patella Muller, 1786; Lepadella Genus Lecane Nitzsch patella after Bory de St. Vincent, 1826. Several authors distinguish the genus Ecology. Littoral species, periphytic, found Monostyla (with only one toe) from Lecane (with occasionally in plankton from reservoirs, rivers two toes). Both genus were initially included in and ponds. Uncommon in large waterbodies. the family Euchlanidue. Edmondson (1935) pro- Cond: 20-823 pS cm-'; Alk: 150-3667 peq 1.'; posed unification, including both in the same pH: 6.7-9.3; Temp: 9.1-22.3 "C. genus Lecane. Later, Bartos (1959) sustained that Morphological features of interest. Outline of Monostyla and Lecane belonged to the family the lorica variable, elliptical, with a food opening Lecanidae, adding also the subgenus also variable U-or-V shaped. Ventral sinus with a Hemimonostyla (intermediate forms where the wider frontal part. Foot-opening with two small fusion of the toes has only been partial). Koste pointed margins. (1978) gave to Hemimonostyla and Monosryla Geographical distribution. Cosmopolite. It is the taxonomic category of subgenus, later Koste the most common species of the genus in the & Shiel (I 990a) separated Lecane and Monostyla Iberian Peninsula. as two different genera, and gives taxonomic Distribution in reservoirs. It has been found in category of genus to Hemimonostyla. More 11 reservoirs spread across the Iberian Peninsula. recently, Segers (1993) questioned the separation of the genus based only on the criteria of the Lepadella rhomboides (Gosse, 1886) (Fig. 15 fusion of the toes, and proposed synonymy d,e; Fig. 16) between Lecane, Monostyla and Hemimonostyla. Metopidia rhomboides Gosse, 1886; Lepadella rhomboides after Harring, 191 3. Lecane (M.) bulla Gosse, 1851 (Fig. 18 a; Fig. Ecology. Periphytic species, heleoplanktonic. It 19) tolerates a wide range of pH (Berzins & Pejler, Monostyla bulla Gosse, 185 1. 1987; Koste & Shiel, 1989b), but prefes alkaline Ecology. Periphytic species, occasionally water. found in plankton samples. Very common among Cond: 250.3-433 pS cm-'; Alk: 2047.3-2519 macrophytes in small waterbodies. The species peq 1-'; pH: 8.26-9; Temp: 24.9-26.7 OC. prefers high concentrations of carbonates. Morphological features of interest. Lorica with Cond: 56.7-3590 pS ern-'; Alk: 51.5-498 peq 1.'; a moderately high arched median keel. Dorsal pH: 6.8-8.2; Temp: 10-19.35 "C sinus U- shaped, and ventral sinus V-shaped. Morphological features of interest. It is charac- Dorsal aperture of the head opening presents a terized by a V-shaped dorsal opening of the lori- collar which can be bordered by a thick granula- ca, and a small U-shaped notch on the posterior ted cuticule. Foot-opening U-shaped, with paral- margin (where the dorsal antenna protrudes). It lel sides. Long distal foot-segment. Toes relative- presents a long toe, ended by a claw with basal ly shorter and slightly curved. spicules and a undivided claw with a medial line Geographical distribution. Cosmopolite. In undivided. Spain it has only been collected in Alacant (Rojo Geographical distribution. Cosmopolite. & Okra, 1986), on the Central Mediterranean Common in the Iberian Peninsula and the coast, and in the Balearic archipelago (De Balearic Islands. Manuel et al., 1992) because of this we expect a Distribution in reservoirs. Its distribution in widespread distribution of this species. Spanish reservoirs is preferentially in eastern

122 de Manuel. J. regions, in reservoirs located in calcareous Cond: 383 pS cm-I; Alk: 3882 peq 1-I; pH: 8.8; basins. Temp: 26.2 "C Morphological features of interest. Head Lecane (M.) closterocerca (Schmarda, 1859) aperture margin slightly convex; concave by (Fig. 18 c) ventral margin. External angles with acute cusps Monostqlla closterocerca Schmarda, 1859. curved internally. Dorsal plate smaller than ven- Ecology. Littoral species, frequently found in tral plate, the latter is strongly convex and is or- plankton samples. Tolerates a wide range of sahnity. namented with divergent folds. Two long toes Cond: 51.5-498 pS cm-'; Alk: 171-3657.7 (more than a quarter of its total body length), peq 1-I; pH: 6.7-9.1; Temp: 7.8-24 "C with slender claws. Morphological features of interest. Head aper- Geographical distribution. Tropical and sub- ture dorsal and ventral margins similar, V-shaped tropical distribution. Rare in the Iberian penin- sinuses with widely-flaring convex sides; trans- sula; it has been recorded previously by verse ventral fold in front of foot. One long Wiszniewski (1931), ArCvalo (1932) and Mi- toe,minor thanU3 body length and without claw: racle (1 976). Geographical distribution. Cosmopolite. It has Distribution in reservoirs. In the latest survey been found accassionally in Spain (Velasco, 1990), it has been found only in summer samples from but it is probably a very common species, wide- the reservoir La Concepcion (1 02). spread in the Iberian peninsula and Balearic arch- pelago. Distribution in reservoirs. It has been found in Lecane (L.)flexilis (Gosse, 1889) (Fig. 17 a; Fig. six localities. 19) Distyla,fzexilis Hudson & Gosse, 1886; Lecarze flexilis after Harring, 1913. Lecane (M.) copeis Harring & Myers, 1926 (Fig. Ecology. Littoral species, occurring occasio- 18 d; Fig. 19) nally in plankton. High tolerance to alkalinity. Monostyla copeis Harring & Myers, 1926. Pejler (1962) found it more frequently in alkaline Ecology. Littoral species. environments, and Koste (1978) records it as Cond: 351 pS cm-I; Alk: 2014.8 peq 1.'; pH: alkalophil. But Koste & Shiel (1990a) found it in 8.37; Temp: 17.9 "C slightly acid water. Morphological features of interest. Head aper- Cond: 22-823 pS cm-'; Alk: 131-3667 peq 1-I; ture margin coincident, slightly concave; trans- pH: 6.64-7.87; Temp: 9.50-21.13 "C verse ventral fold in front of foot, with a short toe Morphological features of interest. Head aper- (less than 1/4 of its total body length) and spin- ture margin coincident and convex, with two dle-shaped. Foot is enlarged in its mid-section short cusps at external angles. Dorsal plate and ended by a short acute claw which allows to facetted. Ventral plate narrower than dorsal. Toes distinguish this species from L. closterocerca. long and slender, approximately a quarter of its Geographical distribution. Cosmopolite. Its total body length. Recurved claw with a small occurrence in reservoirs constitutes the first dorsal basal spicule. record of this species in the Iberian Peninsula. Geographical distribution. Cosmopolite. It is Distribution in reservoirs. Specimens have been a common species in littoral environments, but identified in plankton samples from Sta. Anna (93). scarce in the Iberian Peninsula (Armengol et al., 1975; Guiset, 1976; Morales-Baquero, 1987). Distribution in reservoirs. It has been found in Lecane (L.) crepida (Harring, 1914) (Fig. 17 C; six localities, four reservoirs in the NW of the Fig. 19) Iberian Peninsula. of low mineralizated water. Ecology. Littoral species. Warm stenoterm.

Rotifers of the Spanish reservoirs 125

Lecane (M.) hamata Stokes, 1896 (Fig. 18 b) Distribution in reservoirs. Rare. In the 1987/88 Monostylu hamata stokes, 1896; Lecane survey it was found in summer samples from hamata, after Myers, 1937. Villalcampo (26). Ecology. Periphytic species, littoral. Eurytopa. Cond: 179.3-344 pS cm-'; Alk: 1507.6-2799 Lecane (L.) inermis (Bryce, 1892) (Fig. 17 f; Fig. peq 1-I; pH: 7.9; Temp: 11.9-13.5 "C 19) Morphological features of interest. Head aper- Distyla inermis Bryce, 1892; Lecane inermis, ture with a dorsally narrow U-shaped sinus. after Harring, 1913. Dorsally it presents a V-shaped sinus with two Ecology. Littoral species. Found mostly in rounded in its posterior end cusps. The ventral warm waters, thermal springs, etc. (Kutikova, plate is extended with two acute cusps on either 1970, found it in a geyser environment at side of the head aperture. The dorsal plate pre- 62.5 "C). sents regular facetting. It has a transverse fold and Cond: 14.7 pS cm-'; Alk: 74.7 peq 1-I; pH: 7.3; several longitudinal folds on the ventral plate. It Temp: 19.4 "C has one short and slender toe without claw. Morphological features of interest. Mem- Geographical distribution. Cosmopolite. branous, very flexible lorica, anterior margins Selga (1952) and De Ridder (1962) found it in coincident; ventral plate wider than dorsal, both waterbodies of the Iberian Peninsula. In the without ornamentation. Foot segment rounded, it Balearic archipelago it is a common species; fre- projects beyond the dorsal plate. The second foot quent in farm ponds and drinking troughs (De segment projects beyond the lorica. Toes are Manuel, et al. 1992). short, straight and terminated in an acute Distribution in reservoirs. In the 1987/88 sur- recurved claw almost as long as the toe. vey it has been found in plankton samples from Geographical distribution. Cosmopolite. Rare, two reservoirs during the mixing period: in Spain it has previously been found by Retortillo (69) and Boadella (79). In the 1972/75 Margalef (1948, 1949) and Donner (1970). survey it was found in winter and autumn, in five Distribution in reservoirs. It has been found only reservoirs, all of low mineralization. in the reservoir Chandrexa (22) in the north east of the Iberian Peninsula and only during summer. Lecane (L.)hastafa (Murray, 1913) (Fig. 17 g) Cathypna hastata Murray, 1 9 13; Lecane has- Lecane (L.) luna (Muller, 1776) (Fig. 17 d) tutu, Harring & Myers, 1926. Cercaria lunu Muller, 1776; Lecane luna, after Ecology. Littoral species, often present in fresh Nitzsch, 1827. and slightly brackih waters. Ecology. Littoral and periphytic species. Cond: 541 pS cm-'; Alk: 3038 peq 1-I; pH: 8.1 ; Eurytopic, common in freshwater environments. Temp: 24.3 "C Heleoplanktonic, frequently occurring in plank- Morphological features of interest. Head aper- ton samples. ture margins not coincident; dorsal slightly con- Cond: 14.7-907 pS cm-I; Alk: 74.7-3882 vex, ventral straight. Two small spines at the peq 1-l; pH: 6.3-9.9; Temp: 9.5-26.2 "C external angles. Dorsal plate smaller than ventral, Morphological features qf interest. Head aper- truncated posteriorly. Toes larger than a quarter ture margins not coincident: both with deep of its total body length, terminating in a long lunate sinuses. External angles of ventral sinus acute claw. cusp-like, dorsal sinus angles more blunt. Geographical distribution. Probably cosmopo- Smooth dorsal plate almost circular with a broad lite. It has been collected in waterbodies from medium anterior hump. Ventral plate is slightly Delta de 1'Ebre (Forks et al. 1986) and in coastal narrower with a single transverse fold. Toes are ponds from Mallorca and Menorca (De Manuel et one third of the total body lenght, terminated in a al. 1992). claw with a basal spicule. 126 de Manuel, J.

Geographical distribution. Cosmopolite. It is a gular cusps at external angles. Dorsal plate indis- common, widespread lecanid. tinctly facetted, with anterior row incomplete. Distribution in reservoirs. It has been found in Ventral plate with transverse fold; second foot plankton samples from 20 reservoirs, both in segment visible beyond posterior segment; toes winter and in summer, distributed uniformly are about a quarter of total body length and ter- throughout the Iberian Peninsula. minate in stout claw with a basal spicule. Geographical distribution. Cosmopolite. Lecane (M.) lunaris (Ehrenberg, 1832) (Fig. 18 e; Mainly found in the Pyrenean mountains Fig. 19) (Margalef, 1948b; unpublished data). Lepadella lunaris Ehrenberg, 1832; Monostyla Distribution in reservoirs. It has been only lunaris Ehrenberg, 1838. found in the reservoir Salime (lO), during mix- Ecology. Littoral, it can be considered heleo- ing period. planktonic. This lecanid occurs frequently in the plankton. Eurytopic, it prefers eutrophic water. Lecane (M.) scutata (Harring & Myers, 1926) Cond: 22-1126.3 pS cm-'; Alk: 98-4681.7 (Fig. 18 g ) peq 1.'; pH: 6.3-9.2 ; Temp: 7.2-26.2 "C Monostyla scutata Harring & Myers, 1926; Morphological features of interest. Head Lecane scutata Wiszniewski, 1954 aperture narrow dorsally, with a V-shaped sinus Ecology. Littoral periphytic species. Koste & posteriorly rounded. Ventral margin wide, Shiel (1990a) recorded it is an acidophil species, sinus deep. Transverse dorsal fold at base of common among Sphagnum, but it is probably anterior sinus; toe long and slender, more than more eurytopic. a third of total body lenght, with two annular Cond: 550.6 pS cm-'; Alk: 3468 peq 1.'; pH: constrictions. Claw long, slender, acutely 8.3; Temp: 8.4 "C pointed with two minute basal spicules. Morphological features of interest. Head aper- Diverse morphs and varieties have been ture margins coincident, slightly concave; with described (L. lunaris vay. constricta, Murray, sharp corners but no anterior spines. Lateral sulci 1913; L. lunaris crenata, Harring, 1913; L. are shallow, indistinct transverse fold of ventral lunarisJ: perplexa, Ahlstrom, 1938). plate; toe long, stout, of one third of the total Geographical distribution. Cosmopoli te. body length and parallel-sided then tapering to a Widely distributed through all the Iberian lender acute claw. Peninsula territory. Geographical distribution. Cosmopolite. Rare, Distribution in reservoirs. It has been found in in Spain it has only been collected in ponds in numerous reservoirs (3 l), distributed throughout South-East Spain (Rojo & Okra, 1986) and in Spain during stratified conditions and after mix- reservoirs. ing. In the previous survey it had been collected Distribution in reservoirs. Rare. It has been in plankton samples from 40 localities. found only in winter samples from Entrepeiias (37). In the 1972/75 survey it was collected in Lecane (L.) mira (Murray, 1913) (Fig. 17 b) four localities. Cathypna mira Murray, 1913; Lecane mira after Harring & Myers, 1926. Lecane (M.) stenroosi Meissner, 1908 (Fig. 18 Ecology. Periphytic species; common in slight- h,i; Fig. 19) ly acid waters. Rarely occurring in plankton. Monostyla bicornis Stenroos, 1898; Monostyla Cond: 52 pS cm-I; Alk: 320.2 peq 1.'; pH: 7.2; stenroosi Meissner, 1908; Lecane stenroosi Temp: 10.8 "C Wiszniewski, 1953. Morphological features of interest. Head aper- Ecology. Littoral and periphytic species. ture margins not coincident: dorsal almost Abundant in algal mats in ephemeral ponds straight, ventral slightly concave; two stout trian- (Koste & Shiel, 1990a). Warm stenoterm. Rotifers of the Spanish reservoirs 127

Cond: 383-1 175.6 pS cm-'; Alk: 2251.3-3882 a synonymous of L. (M.)furcatu, but they proba- peq I-]; pH: 8-8.8; Temp: 23.3-26.2 "C bly are two separate species, as there are conside- Morphological .features of interest. Head aper- rable differences between the morphology of the ture dorsally straight, ventrally with shallow lorica, specifically, in the distal part of the foot. rounded sinus with strongly convex sides. Two Cond: 449.7 pS cm-I; Alk: 2773 peq 1-I; pH: short stouts, incurved hooklike frontal spines. 8.3; Temp: 20.5 "C Lateral sulci very deep, particularly in anterior Morphological features of interest. Head aper- half, with characteristic constriction in ventral ture with coincident straight dorsal and ventral plate. Toe is long, stout, about one third of the margins; regular facetting of dorsal plate; ventral total body length, slightly enlarged in middle. plate also with longitudinal markings. Transverse Claw is short, stout and acutely pointed, with two fold in front of foot with two small semicircular basal spicules. folds. Toe long, one third of total body length, Geographical distribution. Cosmopolite. straight with slight taper. Claw long and slender, Found by Wiszniewski (1931) and Arkvalo with a medium line. (1932) in waterbodies in Valkncia (Central Geographical distribution. Cosmopolite. Rare, Mediterranean coast of Spain). it is a new record for the rotifer fauna of the Distribution in reservoirs. Found in summer Iberian Peninsula. samples from La Concepcidn (102) and Iznajar Distribution in reservoirs. Only one specimen (73). In the previous survey it was not found. was collected in summer samples from the reser- voir Sant Ponq (96). Lecane (L.) tenuiseta Harring, 1914 (Fig. 17 e) Ecology. Littoral species. Eurytopic. Family PKOALIDAE Cond: 344 pS cm-'; Alk: 2799 peq I-'; pH: 7.9; Genus Proales Gosse Temp: 13.5 "C Morphological features of interest. Head aper- Proales jullaciosa Wulfert, 1937 (Fig. 20 a,b,c; ture margins parallel, slightly convex; dorsal Fig. 16) plate smooth, rounded posteriorly; ventral plate Ecology. Heleoplanktonic species. Eurytopic, with a series of ridges. Lateral sulci are shallow; it prefers dystrophic ponds. It tolerates wide posterior segment broad, rounded, it protrudes ranges of alkalinity, and may inhabit slightly acid beyond the dorsal plate. The second foot seg- waters too. It feeds on detritus, bacteria, algae, ment is not protruding. The toes are long, slen- and microcrustacea and other invertebrates in der, approximately one third of the total body decomposition (Koste & Shiel, 1990b). length, terminating in extremely long spine-like Cond: 208.8 pS cm-I; Alk: I5 16.2 peq 1-I; pH: claws. 8.39; Temp: 18.84 "C Geographical distribution. Cosmopolite. Rare, Morphological features of' interest. Body it is a new record for the Spanish rotifer fauna. It cylindrical (200 a 300 pm) without lorica, with has also been collected in lake Sanabria (unpu- medial bulge. It presents a soft and flexible cuti- blished data). cle, with longitudinal folds. Small rounded knob Distribution in reservoirs. Scarcity in the projecting dorsally between toes. Oblique coro- reservoir Boadella (79), in samples from the na. Small rostrum present. Virgate trophi, with stratification period. seven teeth in left uncus, right with 5-6 teeth. Munubrium presents a wide lamella. Gastric Lecane (M.) tethis Harring & Myers, 1926 glands are round to elongated. Foot glands with (Fig. 19) reservoirs. It may be confused with Proales Ecology. Periphytic species. It is a rare orga- decipiens, however the latter presents a different nism. Little autoecological information is avai- trophy structure, and does not has the characteris- lable in the literature. Koste (1978) included it as tic dorsal knob between toes.

130 de Manuel. J.

Distribution in reservoirs. It has been found in crum; rami asymmetric, inner edges striate but reservoir Sobron (91), in summer. not denticulate. Eyes not large and lenticular. Geographical distribution. Cosmopolite. This Cephalodella gibba Ehrenberg, 1832 (Fig. 16; is the first record for Iberian rotifer fauna. Fig. 21 h,i) Distribution in reservoirs. It was collected in Furcularia gibba Ehrenberg, 1932; Sobr6n (99), during the summer campaign of the Cephalodella gibba, after Harring & Myers, 1877/88 survey. 1924. Ecology. Heleoplanktonic species, common Notommata copeus Ehrenberg, 1834 (Fig. the littoral areas of fresh and brackish waterbo- 21 j,k) dies. It may occasionally be found in the bran- Notommatus copeus Ehrenberg, 1834. quial chambers of some crustaceans. It feeds on Ecology. Littoral species, occasional in plank- unicellular algae, flagellates and ciliates. It is an ton. It feeds on filamentous algae (Spyrogira, eurytopic species, but it prefers cold waters Zygnema, Mougeotia). It prefers slightly acid Cond: 19.7-950 pS cm-'; Alk: 98.6-3667 peq I-'; waters. pH: 6.6-8.48; Temp: 6.4-18.8 "C Cond: 20 pS cm-'; Alk: 99 peq 1.'; pH: 7; Morphological features of interest. Body Temp: 6 "C slightly elongated, compressed laterally, gibbous Morphological features of interest. Large rump. Lorica with distinct plates. Toes long, species (500- 1000 pm), elongate body, truncated straight or recurved, slender and of one third of posteriorly. Tail with a conical projection with an the body length. Mastax large, with manubrium articulated tip-segment. Foot with two broad seg- strongly crooked, hammer-shaped (Fig. 21 i). ments. Very long ciliate auricles. Long setae on Geographical distribution. Cosmopolite. It has lateral antenna. Mastax virgate, asymmetric, left been found throughout the Iberian Peninsula. side more developed Distribution in reservoirs. It is a relatively Geographical distribution. Cosmopolite. It is common organism in plankton samples of reser- the first record for the Iberian fauna. voirs. In the 1972/75 survey this species was col- Distribution in reservoirs. Only one specimen lected in 22 reservoirs. In the 1987/88 survey it was collected in the reservoir Mao (99), in winter. has been found in 11 reservoirs (Fig. 16), mostly in winter (mixing period). Resticula nyssa Harring & Myers, 1924 (Fig. 21 e-g) Notommata cerberus (Hudson & Gosse, 1886) Ecology. Littoral species, periphytic. It prefers (Fig. 21 b-c) low mineralized and slightly acid waters. Copeus cerberus Hudson & Gosse 1834; Cond: 435.5 pS cm-'; Alk: 3545 peq 1.'; pH: Notommata cerberus, after de Beauchamp (1908) 8.2; Temp: 18.8 "C Ecology. Littoral periphytic species. Morphological features of interest. Vermiform Omnivore, it feeds on rotifers, desmidiaceae, body (300-630 pm), with longitudinal and trans- diatoms and flagellates. It was initially consi- verse striae. Anterior protusion on head corres- dered as an acidophyl species. ponds to the rostrum of other taxa. Foot is join- Cond: 435.5 pS cm-'; Alk: 3545 peq I-'; pH: ted, very short and broad. Toes are short, with a 8.2; Temp: 18.8 "C bulbous basal enlargement, and a type claw. Morphological features of interest. Body slen- Modified virgate mastax. Fulcrum long. Rami tri- der (300-600 pm), integument flexible; slight angular with large asymmetric alulae. Basal transverse folds between head and neck. Tail apophysis prominent (Fig. 21 f). rounded, with median lobe and rudimentary la- Geographical distribution. Probably cosmopo- teral lobes. Toes slender, pointed and short. lite. It is a new record for the Iberian rotifer Mastax virgate, Y-shaped lamellae at base of ful- fauna.

132 de Manuel, J.

Distribution in reservoirs. Found in summer Iberian Peninsula and in the basin of the river samples from Sobrdn (91), in the basin of the Guadalquivir (Fig. 23). river Ebre. Trichocerca porcellus (Gosse, 1886) (Fig. 23; Family TRICHOCERCIDAE Fig. 24 e,f> Genus Trichocerca Lamarck Diurella tigris Bory de St. Vincent, 1824; Munocerca porcellus Gosse, 1886;Coelopuspor- Trichocerca cylindrica (Imhof, 1891) (Fig. 22; cellus, Hudson & Goose, 1886; Rattulus tigris Fig. 23) Stenroos, 1898; Diurella orceklus, Jennings, Mastigocerca cylindrica Imhof, 189 1 ; 1903. Trichocerca cylindrica, after Harring, 19 13. Ecology. Heleoplanktonic species, it is prefe- Ecology. Euplanktonic species. Warm rentially found in oligosaprobic waters. It lays its stenoterm, it prefers low calcium concentrations. eggs inside algae (Aglaucoseria, Fragillaria and This is the only species of the genus that carries Dinobryon). asexual eggs from hatching. Phytofagous, it feeds Cond: 92 pS cm-'; Alk: 332.6 peq 1-'; pH: 7.1; on algae, preferentially Crisophycea (Pourriot, Temp: 9.5 "C 1970). Morphological features of interest. Short, Cond: 14.75-3720 pS cm-'; Alk: 74.7-3038 plump, distinctly curved body. Head sheath sepa- peq 1-l; pH: 7.2-9.6; Temp: 9.5-26.1 "C rated by constriction. Two anterior dorsal cusps, Morphological features of interest. Elongate, the right one slightly curved. Two toes, the left cylindrical body. It presents a very fine, and ven- longer, the right shorter, usually held against ven- trally-curved acute spine on the median dorsal tral abdomen. When the animal is preserved and margin of the lorica. Longitudinal striae in head contracts, cephalic margin may resemble the region with short keel and striates field. Left toe head of a "little pig". Trophi is strongly asym- as long as body, right toe reduced to rudimentary. metric, with left manubrium robust and crooked. Animal occasionally in gelatinous sheath (Fig. The left ramus presents an alula that is much 22,b). Eggs carried attached to parent. Males are longer than the right one. The specimens live toeless. longer in alkaline than in acid waters. The species A population from reservoir Cazalegas were may be confused with 7: musculus, but the mas- observed with large resting eggs (Fig. 22 c-f), of tax presents differential features (Shiel & Koste, approximately 120 pm present both in side the 1992). and detached too. Koste (1978) included Geographical distribution. Cosmopolite. It has Trichocerca chattoni (Beauchamp, 1907). A previously been found in SE Spain by Rojo & Oltra warm stenoterm, as a variety of 7: cylindrica (7: (1986). One would expect a wider distribution. cylindrica chattoni). Size is the main difference Distribution in reservoirs. It has been found in between the two taxa and, indeed it maybe a case Forcadas (13), in winter. of cyclomorphosys. Guiset (1 976) called this species. Trichocerca pusilla (Lauterborn, 1898) Geographical distribution. Cosmopolite if Mastigocerca pusilla, Lauterborn, 1898; both taxa are considered a unique species (i.e. 7: Rattulus pusillus Jennings, 1903; Trichocerca cylindrica has holarctic distribution; 7: cylindrica pusilla, after Harring, 1913. chattoni is pantropical and pansubtropical). It is Ecology. Heleoplanktonic species. Eurytopic, found mostly in the western regions of the Iberian may be found in a wide range of salinities. Some Peninsula. species of the genus Brachionus occasionally Distribution in reservoirs. In the 1987/88 sur- have subitaneous eggs fixed in the lorica. It may vey it has been found in 21 localities (only 19 in suck the contend of the eggs of other plankton summer). Frequent in reservoirs in the NW of the rotifer species (Pourriot, 1970).

Rotifers of the Spanish reservoirs 135

Morphological features of interest. Squared Trichocerca stylata (Gosse, 185 1) body, with arched dorsum. Anterior lorica mar- Monocerca stylata Gosse, 185 1 ; Diurella sty- gin with 8-9 projecting serration. Head clearly lata Eyfert, 1878; Mastigocerca stylata Hudson distinguished by transverse suture. Right toe & Goose, 1886; Rattulus stylatus Jennings, 1903; about one half of the left, slender, easily over- Trichocerca looked. May be confused with 7: stylata, but 7: sfylata after Harring, 1913.. rousseleti is slightly shorter and the ramus pre- Ecology. Planktonic species. Found in small sents a bifurcate alulae. waterbodies, but also in lakes and reservoirs. Geographical distribution. Probably cosmopo- Occasionally this species may attach subitaneous lite. In Spain it has only been collected in reser- eggs onto other planktonic rotifers. As well as 7: voirs and in Pyrenean lakes (Miracle, 1978). pusilla, this species also feeds on the eggs of Distribution in reservoirs. It has been found in other planktonic rotifers (Pourriot, 1970). winter, in six reservoirs from the northwest Spain Cond: 27 pS cm-'; Alk: 107.3 peq 1-I; pH: 7.1; (Fig. 23). Temp: 6.4 "C Morphological features of interest. Body irre- Trichocerca similis (Wierzejski, 1893) (Fig. 23; gular in form, integument very flexible. Foot about Fig. 24 a-d) one half of total body length. Trophi asymmetric, Coelopus similis Wierzejski, 1893; Rattulus fulcrum hammer-shaped and left manubrium lar- bicornis, Western, 1893; Mastigocerca wolgensis ger than right. May be easily confused with 7: Meiszner, 1902; Mastigocerca heterostyla Pusilla. Indeed Ruttner-Kolisko, (1974) suggests Daday, 1903. that both are forms of the same species. Ecology. Planktonic species. It seems to prefer Geographical distribution. Cosmopolite. It has warmer waters. Its feeds on cryptomonadaceae only been collected in the north-east of the and chrysophyceae, specially Mallomonas and Iberian peninsula by Margalef (1948a), and more Dinobryon (Pourriot, 1970). 7: similis attaches its recently also in artificial waterbodies in Menorca asexual eggs to other plankters. It is a common (De Manuel et al. 1992). prey of predators rotifers as Asplanchnu and Distribution in reservoirs. It has been found in Ploesoma (Guiset, 1977~). winter in El Vado (38) and in summer in Mao Cond: 14.7-5326.6 pS cm-'; Alk: 74.7-3882 (99). peq 1.'; pH: 7-9.63; Temp: 9.53-26.2 "C Morphological features of interest. Fusiform Trichocerca vernalis Hauer, 1936 (Fig. 23; Fig. body. Head sheath marked by distinct suture. 24 j ,k) Two characteristic slender, unequal occipital Diurella vernalis Hauer, 1936; Trichocerca spines; two low keels extend back from spines. vernalis, after Wiszniewski, 1954. Foot with two unequal toes, about one third of Ecology. Periphytic species, occasionally total body length. found in the plankton. Rare, it may be found in Geographical distribution. Probably cosmopo- ephemeral ponds, but also in reservoirs. lite. In the Iberian Peninsula it is widespread. It is Cond: 47 pS cm-I; Alk: 385 peq 1-l; pH: 7.3; also common in the Balearic archipelago (De Temp: 7.37 OC Manuel et al., 1992). Morphological features of interest. Squat, Distribution in reservoirs. It is the most com- vaulted to conical body. Left anterior margin with mon species of the genus Trichocerca collected in large rounded plate. Foot and toes curved for- Spanish reservoirs. In the 1987/88 survey it was ward. Asymmetric trophi, with a relatively big found in 38 samples (preferentially in summer), left manubrium, "hoquey-stick"-shaped; right corresponding to 35 localities. In the 1972/76 sur- manubrium small, fragile and thin. Details of the vey it was collected in 41 reservoirs, though rarely mastax help distinguish it from 7: brachiura in the Duero and Ebre river basins. (Gosse). 136 de Manuel, 3

Geographical distribution. Cosmopolite. It is a Anapus ovalis Bergendal, 1892; Chromogaster new record for the Iberian fauna. testudo Lauterborn, 1893; Ascomorpha testudo Distribution in reservoirs. Several specimens Zacharias, 1894; Anapus testudo Weber, 1898; were identified from winter samples of Burguillo Ascomorpha ovalis, after Carlin, 1943. (42), a reservoir located in the basin of the river Ecology. Planktonic species frequent in lakes Taj 0. and ponds. It prefers alkaline and bicarbonated water. It feeds on dinoflallegates, especially Family GASTROPODIDAE Ceratium. Its maxima coincides with those of Genus Ascomorpha Perty Ceratium (Ruttner- Kolisko, 1974). Cond: -1107 pS cm-I; Alk: 321.3-3711.2 Ascomorpha ecaudis (Perty, 1850) (Fig. 25 c; peq 1-I: pH: 7.8-9.3; Temp: 24.8-10 "C Fig. 26); Sacculus viridis Bergendal, 185 1; Morphologicalfeatures of interest. Lorica consti- Ascomorpha helvetica Perty, 1 852; Ascomorpha tuted by two plates. Ventral plate oval. Variable num- germanica, Leydig, 1854. ber of accretion bodies and chromatophores in sto- Ecology. Planktonic species, occasionally pre- mach wall. Trophi stylet-shaped, with hypofarinx for sent in periphyton. It prefers warm waters and is sucking the contents of Ceratium cells. Attachment more abundant in spring and autumn. According to to algae is done with a sickle-shaped palp. Pourriot (1965), it feeds on flagellate algae Geographical distribution. Cosmopolite. (Chlamidomonas, Trachelomonas, Cryptomonas). Widespread in Spain. Stemberger (1987) noted the importance of the Distribution in reservoirs. It was found to be mucus mass for catching food. This mass is found widespread in Spanish reservoirs, especially in surronding the animal (may be 1 mm in diameter, summer. More frequent in the East where waters but is usually absent in preserved material). Food are typically of moderate to high alkalinity. caught in the mucus is carried to the mouth thanks to a current caused by cilia movement. Mucus also Ascomorpha sultans Bartsch, 1870 (Fig. gives protection from some predators. A. ecaudis 25 e; 26) may have symbiotic algae (Zoochlorella) within Sacculirs hyalinus Kellicott, 1888; Ascomorpha stomach wall cells. agilis Zacharias, 1893; Ascomorpha hyalina, Cond: 282.2 pS cm"; Alk: 2002 peq 1-I; pH: Jennings, 1901. 8.14; Temp: 25.10 "C Ecology. Planktonic species, inhabiting pelag- Morphological features of interest. It is cha- ic and littoral environments. More frequent in racterized by the presence of four faecal bags summer and autumn. Like A. sultans, its abun- forming a square. No apical tentacle. Spiny rest- dance is associated to the developing of ing eggs. The analysis of a mastax is necessary to Ceratium. According to Pourriot (1976), it also distinguish A. ecaudis from other species of the feeds on Uroglena and peridinidae. A. saltans CO- genus. Rami allules are triangular, with charac- occurred in seven localities with A. ovalis (Fig. teristic acute margins. 25), in spite of the fact this last species inhabits Geographical distribution. Probably cosmopo- more alkaline environments. lite. Frequent in Pyrenean lakes (unpublished Cond: 41-1175 pS cm-'; Alk: 6.3-3882 peq 1-I; data). Rare. pH: 6.6-9.3; Temp: 6.4-26.7 "C Distribution in reservoirs. A. ecaudis has only Morphological .features of interest. It presents been found in La Minilla (84) in both surveys. Its one large fecal sac (i.e. accretion body). Trophi presence in La Minilla constitutes the Southern- with well developed manubrium. Like A. ovalis, it most record of this species in the Iberian peninsula. presents a palp in the apical field. Chromatophores in stomach wall cells. Ascomorpha ovalis (Bergendal, 1892) (Fig. 25 d; Geographical distribution. Cosmopolite. In Fig. 26) Spain it is common in reservoirs, but there are

Rotifers of the Spanish reservoirs 139

Distribution in reservoirs. It has been found in dolichoptera in the stomache contents of winter samples from the reservoir Fervenza ( 13, Asplanchnn and Ploesoma. the Westermost reservoir of those studied under a Cond: 27-3590 pS cm-'; Alk: 98-387 1.7 peq 1.'; oceanic-marine climatic regime. pH: 6.33-9.18; Temp: 5.9-26.2 "C Morphological features of interest. Polyarthra Gastropus stylifer (Imhof, 1891) (Fig. 25; is a genus with controversial systematics. For ins- Fig. 26) tance, it is difficult to discriminate between l? Notops pigmaeus Calman, 1892; Hudsonella dolichoptera and l? vulgaris only attending to picta Zacharias, 1893; Sacculus orbicularis morphology. Both species have ventral finlets, but Kellicott, 1897. with differences difficult to distinguish under an Ecology. Planktonic species. Warm stenoterm. optic microscope (Fig. 27 h,i). Lateral blades of l? According to Braioni & Gelmini (1983) this vulgaris are relatively broader and shorter than in species is found in assembly with some colonial P. dolichoptera, with differences in the serrated algae like Volvox and Dinobryon. margins (Fig. 27 0.The body ofl? dolichoptera is Cond: 197.2-1065 pS cm-l; Alk: 1210.3-3486 slightly smaller than that of l? vulgaris. Resting peq I-'; pH: 7.8-8.4; Temp: 10.6-21 "C eggs are always double-shelled with folded skin Morphological ,features of interest. Ventral within shells (Fig. 27). There are also differences foot, protruding from the middle of the body; one between both species in mastax morphology, spe- triangular toe. Anterior margin of cuticle undula- cially in details oframi (Koste, pers. corn.). Guiset ted (this character may be observed in contracted ( 1977b) distinguishes Polyarthra species by specimens). Vitellarium with 4-8 nuclei. Tube of mesuring the dimensions of diagnostic traits: ful- prepharinx long and slender for sucking cell con- crum length, resting egg and subitaneus egg tent of dinoflagellates. diameters. Pejler (I 956) maintained introgression Geographical distribution. Cosmopolite. In between both species to explain that some indi- the Iberian peninsula it has only been found in viduals can have intermediate characters between reservoirs and in plankton samples from some both species (Fig. 27 j,k). Pyrenean ponds (unpublished data). Geographical distribution. Cosmopolite. It is Distribution in reservoirs. It has been found widespread throughout the Iberian Peninsula, distributed across the basin of the river Ebre: i.e but it is likely that some records of P. Ebro, (6); Urrunaga, (4); Sta. Anna, (93); dolichoptera in reality correspond to P. vulgaris Mequinenza, (4). It the previous 1972/76 survey, and viceversa. it was collected in two Northern reservoirs, too. Distribution in resenvirs. It is very common and its occurrence is higher in winter than in Family SYNCHAETZDA E summer. In some reservoirs it may be confined to the hypolimnion during the stratification period. Genus Pulyarthra Ehrenberg In the 1987/88 survey it was collected in 31 localities in winter and 14 in summer. Polyarthra dolichoptera (Idelson, 1925) (Fig. 27) Polyarthra platyptera var. dolichoptera Polyarthra euryptera (Wierzejski, 1893) (Fig. Idelson, 1925; Polyarthra dolichoptera, after 27; Fig. 28) Carlin, 1943. Polyarthra plutyptera var: euryptera Wier- Ecology. Euplanktonic species; cold steno- zejslu, 1893. term, it tolerates low oxygen concentrations Ecology. Euplanktonic species. Warm steno- (Ruttner-Kolisko, 1974). Pourriot (1 977) found term. It prefers low alkalinity and eutrophic wa- that Polyarthra feeds on mainly cryp- ters. Seasonal in Mediterranean latitudes, with tomanadaceae, chrysophyceae and central dia- maxima in summer. More abundant in the epi- toms. Guiset (1977~)frequently found P. limnion during the stratification period. P. 140 de Manuel, J. euryptera may be occasional prey for some Polyarthra platyptera var: remata Skorikov, predator rotifers such as Asplanchna girodi and 1896. Ploesoma hudsoni (Guiset, 1977 c). Ecology. Planktonic species, occasionally Cond: 14-1175.6 pS cm-'; Alk: 58.2-3711.2 found in littoral environments. Miracle (1976) peq 1-I; pH: 6.3-9.9; Temp: 5.9-24.9 "C found it in Lake Banyoles (NE Spain). Its abun- Morphological features of interest. Large (150- dance is strongly correlated with temperature. It 170 pm). Vitellarium with 12 nuclei. Blades prefers to alkaline waters. It feeds mainly on fla- feather- like, broad (30 - 70 pm), shorter than the gellates. It is often found associated to other body length, with a serrated margin and lateral species of Polyarthra. It is usually prey to nerves (Fig. 27 c). No ventral finlets. Resting eggs Ploesoma hudsoni and species of the genus large (85- 110 pm), usually double-shelled, with Asplanchna (Guiset, 1977 c). folded skm between shells (Fig. 27 b). Cond: 14.7-3590 pS cm-I; Alk: 74.7-3871.7 Geographical distribution. Cosmopolite. In peq 1-l; pH: 6.64-10; Temp: 6.4-25.7 "C the Iberian Peninsula it has been found in various Morphological features of interest. It is the localities, mainly in reservoirs (Guiset, 1976). smallest species of the genus (<120pm) found in Distribution in reservoirs. In the 1987188 survey reservoirs. Blades serrated, sword-shaped (Fig. it was found in 13 reservoirs, nine in the stratifica- 27 g) and of equal length; longer than body. No tion period and five in the mixing period. Guiset ventral finlets. The number of nuclei and the (1976), in the previous survey, found it in 40 locali- absence of ventral finlets permit to distinguish ties, more often in reservoirs in the NW of Spain. this species from l? dolichoptera. Both species may be easily confused in preserved material. Polyarthra major (Burckhardt, 1900) (Fig. 27; Geographical distribution. Cosmopolite. Fig. 28) Widespread throughout all the Iberian Peninsula. Polyarthra platyptera var: major Burckhardt, Distribution in reservoirs. Frequent in stratifi- 1900. cation and mixing periods. It has been found in Ecology. Euplanktonic species, eurithermic in more than half of reservoirs (Fig. 28). oligotrophic waters. In large waterbodies it often co-occurs with other species of the genus (Table Polyarthra vulgaris (Carlin, 1943) (Fig. 27) 3). It has been found in the stomache content of Polyarthra trigla Ehrenberg, 1834; Polyarthra Asplanchna girodi (Guiset 1977 c). trigla vulgaris Pourriot, 1965. Cond: 14-1423.5 pS cm-'; Alk: 58.2-3711.2 Ecology. Euplanktonic species. Euritherm and peq 1-I; pH: 6.3-10; Temp: 6.45-25.5 "C perennial. It prefers superficial waters and very Morphological features of interest. No ventral oxygenated environments (it is rarely found in finlets. Blades broad (20- 30 pm), feather-shaped hypolimnion). According to Pourriot (1977) it (Fig. 27 b); length of blades less than a body feeds on cryptomonadaceae, chrysophyceae and length. Body larger than P. vulgaris and P. central diatoms. Guiset (1977~)found P. vulgaris dolichoptera. Vitellarium with 8 nuclei. was a frequent prey of Asplanchna and Geographical distribution. Cosmopolite. It has Ploesoma. been found throughout the Iberian Peninsula. Cond: 14-3720 pS cm-I; Alk: 68.3-4681.7 Distribution in reservoirs. Relatively higher peq I-'; pH: 6.6-9.9; Temp: 5.9-26.7 "C occurrence during the stratification period. Morphological features of interest. Ventral fin- Frequently in both summer and winter samples lets setiform and smooth (Fig. 27 h). Vitellarium (i.e. found in 51 reservoirs in winter and in 46 with eight nuclei. Blades as long as body (8-20 reservoirs in summer). pm broad), feather-like and slightly serrated (Fig. 27 ej,k). Form and length of blades are not good Polyarthra remata (Skorikov, 1896)(Fig. 27; characters to separate this species from P. Fig. 28) dolichoptera. Both species have highly variable

144 de Manuel, J. and various algae. Guiset (1977c), studied the Peiiarroya (53, in the basin of the river Gua- stomach content of some populations of l? kud- diana. it was then suggested that the species had soni, he found diatoms, dinoflagellates, volvo- probably colonized the reservoir from the Lakes cales, chlorococales, desmidiaceae and rotifers of Ruidera (Guiset, 1976). In the 1987/88 survey (species of the genus Polyarthra, Synchaeta, it was found in El Grado (81), in summer and Keratella and Trichocerca. As well as relatively far away from Peiiarroya, suggesting Asplanchna priodonta, another predator rotifer). that the species had colonized from Pyrenean Cond: 14-293 pS cm-'; Alk: 58.2-2470 peq 1-l; lakes (in these, l? truncatum has not been recorded pH: 6.3-9.67; Temp: 7.8-23.9 "C yet, but may be highly seasonal and therefore dif- Morphological features of interest. Large (300 ficult to observe. to 600 pm). Lorica presents blisters or vacuoli ventraly situated, giving at the specie a "bubbly" Genus Synchaeta Ehrenberg, 1832. appearance. No ventral furrow. Foot long, annu- lar, ended with two large toes. Head with two fin- Synchaeta kitina (Rousselet, 1902) (Fig. 30 c,d; ger-like palps. Large virgate trophy, that may be Fig. 31) partially projected to catch prey. Synchaeta tremula var: kitina Rousselet, 1902; Geographical distribution. Holartic (Koste, Synchaeta kitina Stemberger 1978). In the Iberian Peninsula it has been identi- Ecology. Euplanktonic species, it prefers fied mostly in north-western waterbodies, but slightly alkaline waters. High tolerance to salini- also in other northern localities (Margalef, 1973; ty. During stratification it inhabits the epilimnion Miracle, 1978; Telleria, 1981). It is also frequent and its abundance is reduced with depth (Guiset, in Pyrenean lakes (unpublished data). pers. corn.). S. kitina may carry subitaneous eggs Distribution in reservoirs. Mostly found in sum- during a short time, but also eggs attached to mer, in reservoirs from the north-west of Spain. planktonic diatoms have been also observed. Frequent in reservoirs of the river Miiio basin. It Cond: 20-1126 pS cm-'; Alk: 146.5-3468 has increased its area of distribution with respect to peq 1.'; pH: 6.2-8.9; Temp: 7.3-24 "C the previous study of the reservoirs (Fig. 31). Molphological features of interest. Cone-shaped body (not contracted specimens). Head more or less Ploesoma truncatum (Levander, 1894) (Fig. 4. flat. Externally very similar to S. tremula and S. 28; Fig. 31) oblonga. Size differences may be found (e.g. S. kiti- Gastroschiza truncata Levander, 1894; na is smaller), in the situation of the lateral antennae Ploesoma truncatum after Weber, 1898. (e.g. in the case of S. kitina these are located on the Ecology. Planktonic species. It may also be base of the foot). All this characters, however, are found in the littoral area, too. Warm stenoterm. It difficult to see occulted in material that has been feeds on algae and other rotifers (Koste, 1982). preserved. The main diagnostic characters are mor- Cond: 291 pS cm-'; Alk: 2206 peq 1.'; pH: 8.4; phological (Fig. 30 c), particularly the shape and Temp: 18.4 "C morphology of teeth in uncus (Stemberguer, 1979). Morphological features of interest. Smaller Resting eggs presents small spines. than l? hudsoni (1 50-300 pm). Lorica ringed with Geographical distribution. Cosmopolite. ventral furrow. Head-shield present, without Uniformly distributed throughout the Iberian teeth. Eye red. Head with two finger-like palps. Peninsula. S. kitina occurs mainly in coastal Geographical distribution. Probably cosmopo- ponds and lagoons (MenCndez & Comin, 1986; lite. Rare. In Spain it had previously been col- Forks et al., 1986; Oltra & Miracle, 1984; Pretus lected in some reservoirs and in the Lakes of et al., 1992). It is difficult to distinguish from Ruidera (Armengol et al., 1975) other species of its genus (e.g. S. littoralis, Distribution in reservoirs. In the previous Rousselet), which can be found the same envi- study of the Spanish reservoirs it was found in ronments.

146 de Manuel, J.

Distribution in reservoirs. In the 1987/88 Synchaeta pectinata (Ehrenberg, 1832) (Fig. study this species was not as abundant as other 30 e,g> species of the genus. It was found in six reser- Synchaeta inordax Gosse, 185 1; Hydatina voirs in summer and 11 in winter. In the 1972/76 pectinata Acloque 1899. study of the reservoirs its recorded occurrence Ecology. Euplanktonic species. Eurioic, peren- was higher (37 localities). nial, it presents its maxima at low temperature. It may inhabit both small and large waterbodies. Synchaeta oblonga (Ehrenberg, 1832) (Fig. Phytophagus, it feeds on cryptomonadaceae, 30 a,b) chrysophyceae, and central diatoms (Pourriot, Synchaeta neglecta Zacharias, 1901; Synchaeta 1970). It is frequently found infected by the pectinata$ minor Wesenberg- Lund, 1930. microsporid Plistophora (Bertramia) asperospo- Ecology. Euplanktonic species. Euritherm, ra (Fig. 30 e). but its abundance is higher in winter. More fre- Cond: 14-1522.6 pS cm-'; Alk: 58.2-4681.7 quent in alkaline and eutrophic waters. High peq 1.'; pH: 6.3-9.3; Temp: 5.9-25.5 "C tolerance to salinity. It feeds on cryptomon- Morphological features of interest. It presents adaceae and central diatoms (Pourriot, 1970). It two bristle-bearing apical tentacles. Length < 5 10 often carries its eggs during a short time. S. pm. Single eye. Teeth with pointed tips. Asexual oblonga is a common prey of Asplanchna eggs with oil drops and gelatinous case; resting (Guiset, 1977~). eggs with blisters or short spines. Short foot, of Cond: 35-5326.6 pS cm-'; Alk: 58.2-468 1.7 conical shape, with two equal and relatively short peq 1.'; pH: 6.3-8.8; Temp: 5.9-22.8 "C toes. Vitellarium with eight large nuclei. Ruttner- Morphological features of interest. Body well- Kolisko (1 974) defined the stylata-pectinata shaped (<250 pm), head convex. No apical tenta- group, constituted by a series of closely-related cles and double cerebral eye. Smaller than S. and very similar species. pectinata. However, in fixed specimens size is Geographical distribution. Cosmopolite. S. not sufficient to distinguish them and it is often pectinata is a widespread species in Spain. necessary to examine mastax morphology. Distribution in reservoirs. In the 1987/88 survey Specifically, size of the trophy and the unc comb- it was found in 30 reservoirs in summer and in 59 in like ends (Fig. 30 b), are the characters to look winter. No pattern of distribution was apparent. for. Confusion is common with S. kitina and S. tremula, which may coexist. Carlin (1943) and Synchaeta stylata (Wierzejski, 1893) (Fig. 30 Pejler (1957) suggested that S. oblonga, S. tre- f,h,i; Fig. 31) mula and S. lakowitziana, were considered to be Synchaeta wesenberg-lundi Pejler, 1957. the same species, but later Pejler (1962) recog- Ecology. Euplanktonic species, inhabitant of nized them as three separate species. Ruttner- large waterbodies. Warm stenoterm; markedly Kolisko (1974) grouped theses three taxa seasonal (summer). (Synchaeta g. tremula-oblonga). Perhaps a revi- Cond: 47.3-1423.5 pS cm-I; Alk: 225-3562.5 sion of the genus is necessary, for example, the peq I-'; pH: 7.1-9.9; Temp: 8.7-25.5 "C morphology of the mastax under SEM as a diag- Morphological features of interest. Body bell- nostic criterion. shaped, or as a plump to slender cone. Head con- Geographical distribution. Cosmopolite. In vex, no apical tentacles. Very similar to the Iberian Peninsula it has been recorded mostly Synchaeta pectinata, but terminated with a slen- in reservoirs. der foot with a long toe. Subitaneous eggs with Distribution in reservoirs. It was one of the most oil drops and long thin bristles (Fig. 30 f). Teeth common rotifers in the 1987/88 survey mainly dur- with pointed tips (Fig. 30 h). ing the mixing period (58 reservoirs). In the Geographical distribution. Cosmopolite. It 1972/76 study it was found in only 21 localities. presents a northern distribution in Spain, but it

Rotifers of the Spanish reservoirs 149

Distribution in reservoirs. In the 1987188 sur- the Iberian Peninsula. It is also common in Py- vey it was found in summer samples from five renean lakes. reservoirs. In the previous study it was collected Distribution in reservoirs. Very common; it in seven localities, six of them during summer. has been found in 123 samples. In both studies it occurred in approximately the same frequency in Asplanchna girodi (De Guerne, 1888) (Fig.32 f; the stratification and the mixing periods. Fig. 33) Ecology. Planktonic species, occasionally lit- Family TESTUDINELLIDAE toral. It prefers eutrophic and slightly alkaline Genus Pompholyx Gosse waters. Guiset (1977~)found A. girodi feeds po- sitively selecting species of Synchaeta, small Pompholyx sulcata (Hudson, 1885) (Fig. 34 c-g) Trichocerca and Polyarthra vulgaris/dolichop- Ecology. Euplanktonic species. Euriterm in tera. Recently, Pompholyx sulcata and fresh and braclush waters. Feeds on detritus and Keratella cochlearis J: tecta have also been bacteria (Pourriot, 1977). It prefers eutrophic found in its stomach content. A. girodi probably environments. Asexual eggs attached to lorica by is in competition with the predator rotifer a filiform structure (Fig. 34 c). It is predated by Ploesoma hudsoni. Asplanchna girodi (Guiset, 1977c) and may be Cond: 31.5-3720 pS cm-I; Alk: 58-3882 peq I-I; parasitized by the sporozoa Plistophora asper- pH: 6.3-9.9; Temp: 7.7-26.2 "C ospora. Morphological features of interest. Protone- Cond: 45-1126.3 pS cm-I; Alk: 225-3882 phridia with 16 flame bulbs, 50 nuclei in vitellari- peq I-'; pH: 7-10.2; Temp: 6.4-26.2 "C um. The morphology of the mastax is the main dis- Morphological features of interest. Lorica not tinguishable feature of ths species (Fig. 32 0. flattened dorso-ventrally. It presents four lobules, Geographical distribution. Cosmopolite. It is two lateral, one ventral and one dorsal (cross sec- widespread in the Iberian Peninsula. tion as in Fig. 33, d). This is the main difference Distribution in reservoirs. It has been found in with the similar species Fi triloba. It presents cyclo- 21 samples, from I8 reservoirs. A. girodi is more morphosis, i.e. in winter it is slightly larger, with a frequent in summer. longer lorica, than in summer (Fig 34 e,f,g). Cloacal opening, where asexual eggs are attached Asplanchna priodonta Gosse, 1850 (Fig. 33 a-c, e) is slightly curved ventrally. Eggs are round, up to Asplanchna krameri De Guerne, 1888; 75 pm in size and sometimes carried on a retractile Asplanchna priodonta pelagica Zacharias, 1892. thread from a secretory gland. Resting eggs are Ecology. Euplanktonic species. Euriterm and dark, smooth and double-shelled. perennial. Poliphagus, it feeds preferentially on Geographical distribution. Cosmopolite. It has plankton diatoms, dinoflagellates and rotifers. Its been found in some localities in Spain. Its occur- diet is less carnivorous than that of A. girodi rence and abundance in reservoirs is high. (Guiset, 1977; Gilbert, 1980). Distribution in reservoirs. It has been found in Cond: 19.6-1385 pS cm-l; Alk: 98-4681 peq 1.'; 65 reservoirs. More frequent and abundant during pH: 6.3-9.67; Temp: 5.9-25.9 "C the stratification period. P. sulcata has increased Morphological features of interest. Easily dis- its distribution area in relation to that delimitated tinguishable from other species of its genus look- by the 1972/76 survey. In this latter survey it was ing at the morphology of the mastax (Fig. 32 e): found in 68 samples from 39 localities. p.e. robust, acute uncus, rami serrated on inner edges, broad and free ends. Protonephridia are Genus Testudinella Bory de St. Vincent compact, with 4 flame bulbs each. Geographical distribution. Cosmopolite. It is the Testudinella emarginula (Stenroos, 1898) (Fig. most common species of the genus Asplanchna in 34 b)

152 de Manuel, J.

Pterodina emarginula Stenroos, 1898; a branched vitellarium and by differences in the api- Pterodina incisa Harring, 19 13; Pterodina emar- cal zone of lorica. ginula von Hofsten, 1909; Testudinella emargin- Geographical distribution. Cosmopolite. ula after Carlin, 1939; Testudinella incisa var: Recorded frequently in all the Iberian peninsula emarginula, Koste, 1978. and Balearic archipelago. It is found specially in Ecology. Periphytic species; occasionally it reservoirs and littoral ponds. may be found in plankton. Cold stenoterm, it tol- Distribution in reservoirs. In the 1987/88 sur- erates a wide range of alkalinity, but may be col- vey it was collected in six reservoirs. In Forcadas lected in slightly acid waters. Its autoecology is (13) and Fervenza (15) the form 7: patina den- not well-known. dradena (Fig 34 a) was identified. In the previ- Cond: 51.5- 262 pS cm-I; Alk: 171- 2003 ous survey Testudinella patina was found in four peq 1.'; pH: 6.8-7.5; Temp: 7.7-7.8 OC localities. Morphological features of interest. Oval lori- ca, "boomerang"-shaped in section, slightly con- Family CONOCHILIIDAE vex dorsally. Long foot, protruding from a circu- Genus Conochilus Ehrenberg lar foot opening on the ventral plate of the lorica. Traditionally both genera, Conochilus and Geographical distribution. Probably cosmopo- Conochiloides, have been considered separately, lite. It was first recorded in Spanish reservoirs by on the basis of differences in the position of the Guiset (1976). In the Iberian peninsula it has lateral antenna. This fact is very dependent on the been found in ponds from Northwest and in coloniality of the species. Ruttner-Kolisko (1974) Spanish Central region of La Mancha (unpu- considered that this feature was not sufficient to blished data). warrant the separation into two genera. Distribution in reservoirs. Guiset (1976) found it in Fervenza (15). In the 1987/88 survey it was Conochilus coenobasis (Skorikov, 1914) (Fig. 35 also found in winter samples in As Conxas(20), m,n> albeit in low numbars. Conochiloides coenobasis Skorikov, 1914; Conochilus dossuarius var coenobasis, Koste, Testudinella patina (Hermann, 1783) (Fig. 34 a) 1978. Brachionus patina Hermann, 1783; Probos- Ecology. Euplanktonic species. Warm stenoterm. kidia patina Bory de St. Vincent, 1826; Pterodina It feeds preferentially on Trachelomonas (Koste, patina Ehrenberg, 1830; Pterodina valvata 1978). The anphoteric reproduction of ths species Hudson, 187 1; Testudinella patina after Harring, (capacity of females to produce asexual and sexual 1913. eggs at the same time) has been described. Ecology. Heleoplanktonic species. It occurs in Cond: 41-202.3 pS cm-I; Alk: 68.3-711.5 plankton when there is abundance of phytoben- peq 1-l; pH: 6.3-9.2; Temp: 7.4-25.2 OC thos and macrophytes. Euriterm and eurihaline, it Morphological features of interest. Both ven- tolerates high salinity. It feeds mainly on tral antenna are fused and are situated below the Chlorella and diatoms. corona. Mouth in the middle of the corona. Cond: 50-541 pS cm-l; Alk: 98-3545.5 peq 1.'; Asymmetric trophy, with three larger teeth on pH: 6.3-8-89; Temp: 9.5-24.3 "C each uncus. Koste (1978) considered this taxon Morphological features of interest. Lorica almost as a variety of the species Conochilus dossuarius circular in outline, transparent and depressed, (Hudson, 1885); differences should be found strongly flattened dorso-ventrally. Circular foot looking at the morphology of the uncus (Fig. 35, opening located almost in the middle of the ventral bm). face; foot wrinkled, toes replaced by a circle of cilia. Geographical distribution. Cosmopolite. In The form 7: patina dendradena (Beauchamp, the peninsular territory it has only been found in 1955), was found in two reservoirs characterized by reservoirs (Guiset, 1976).

154 de Manuel, J.

Distribution in reservoirs. It is was collected in shaped. Foot once extended may double the length eight reservoirs, all located in the northwestern of the body. In preserved material colonies are usu- region of the Iberian Peninsula. ally total o partially broken (Fig. 35 e). Geographical distribution. Cosmopolite. In Conochilus dossuarius (Hudson, 1885) (Fig. 35 the Iberian peninsula it has only been found in the a,b) Spanish reservoirs (Guiset, 1976). Cephalosiphon dossuurius Hudson, 1886; Distribution in reservoirs. In the 1987/88 sur- Conochiloides dossuarius after Hlava, 1904. vey it was found in four localities, all located in Ecology. Euplanktonic species, warm the north. In the previous study, C. hippocrepis stenoterm. More common in superficial waters. It was more frequently observed, and was collected prefers low alkalinity. According to Boon & Shiel in 30 samples from 20 reservoirs. ( 1990) it feeds on bacteria. Cond: 48-1035 pS cm-I; Alk: 169-2480 peq I-'; Conochilus natans (Seligo, 1900) (Fig. 35 j-1; pH: 6.8-9.1; Temp: 6.4-24.6 "C Fig. 36) Morphological features of interest. Ventral Tubicolaria natans Seligo, 1900; Conochilus antenna partly fused. Foot slender. Trophy asym- natans after Voigt, 1904; Conochiloides natans metrical, with three large teeth on one uncus and after Hlava, 1904. five on the other (Fig. 35, b). Ecology. Euplanktonic species. Cold Geographical distribution. Cosmopolite. stenoterm; it may be very abundant in lakes and Previous Iberian records of this species can only ponds. Solitary, never colonial. be found in Monteiro (1984), in Portugal and in Cond: 22-214.6 pS cm-'; Alk: 58.2-767.4 Guiset (1976) in Spanish reservoirs and in peq 1-I; pH: 6.3-8.6; Temp: 6-20.5 "C ephemeral ponds of Dofiana National Park Morphological features of interest. Ventral (Mazuelos et al., 1993). antennae are long and separate. Posterior end of Distribution in reservoirs. In the 1987/88 sur- the body is surrounded by a gelatinous case vey it was identified in seven reservoirs. In the where eggs are placed. Trophi symmetric, with previous study of 1972/76 it had been found in five or six large teeth on each uncus (Fig 35 k). six localities all in the northwestern region of the Geographical distribution. Cosmopolite. In Iberian Peninsula. the Iberian Peninsula previous records are found in Margalef (1949) from ponds in Baix Urge11 Conochilus hippocreppis (Schrank, 1803) (Fig. (NE, Spain). 35 c-e; Fig. 36) Distribution in reservoirs. It has been found in Linza hippocrepis Skorikov, 1803; Conochilus five localities, in the NE of Spain and preferen- volvox Ehrenberg, 1834; Ptygura volvox tially in winter (Fig. 36). Dujardin, 1841; Megalotrocha volvox, Gosse, 1862; volvox, Schoch, 1868. Conochilus unicornis (Rousselet, 1892) (Fig. 35 Ecology. Planktonic species, it may be found f-i; Fig. 36 ) both in ponds and larger waterbodies. Colonial, it Conochilus leptopus Forbes, 1893; Conochilus may form colonies of 30 to 60 individuals, joined limneticus Stenroos, 1898; Conochilus norvegi- in a gelatinous case. C. hippocreppis is a detriti- cus Burckhard, 1943. vore, probably feeding on bacteria (Pourriot, Ecology. Euplanktonic species. Colonial; it 1977). form colonies of five to 12 individuals. The Cond: 25.8-206.3 pS cm-I;Alk: 98-1767 peq 1-I; colony is encased in a gelatinous sheath. Seaso- pH: 6.3-8.3; Temp: 6.4-15.4 "C nal, it is more frequent in summer. It prefers low Morphologicalfeatures of interest. Ventral anten- to moderate eutrophy. nae located on the apical field, either completely Cond: 50-576.5 pS cm-'; Alk: 98-2002.6 separate or only partly fused. Corona "horseshoe"- peq 1-I; pH: 6.3-8.89; Temp: 7.3-21.2 "C

158 de Manuel. J

Distribution in reservoirs. In the 1987188 survey it Geographical distribution. Cosmopolite. was found in 17 localities, mainly in western Widespread in the Iberian peninsula, but records region, where there is a predominance of siliceous are uncertain, Velasco (1990) (E longiseta / lim- materials. It was more commonly found during netica; E longiseta / terminalis). Probably some stratification period. In the previous survey it was of these records correspond to E hofmanni collected in 39 samples from 34 reservoirs. (Koste, 1980). Distribution in reservoirs. It occurs mainly in Family FILINIIDAE summer, in 20 reservoirs. During the mixing period Genus Filinia Bory de St. Vincent it was found in 13 reservoirs. F: longiseta has an There is considerable controversy around uniform distribution throughout Spain. In the previ- classification criteria for species of the genus ous survey it was collected in18 localities, and the Filinia. The suggestions given by Ruttner- limnetica form was found in 30 reservoirs. Kolisko (1974), based on the biometry of bris- tles (total length, proportion body length, loca- Filinia opoliensis (Zacharias, 1898) (Fig. 39 e-g; tion) are not enough sufficient to be discrimi- Fig. 41) nate at the species level. In addition, these Tetramastix opoliensis Zacharias, I 898; characters have strong variability (Miracle, Filinia opoliensis after Remane, 1933. 1976). Koste (1 980), proposed a systhematics Ecology. Euplanktonic species. Warm based on the trophi morphology (mainly on the stenoterm. It is found preferentially in large number of teeth on uncus). However, in this waterbodies with low alkalinity. paper the criteria of Ruttner-Kolisko using fea- Cond: 48-5326.6 pS cm-'; Alk: 266-3882 tures of the bristles, has been adopted for this peq 1.'; pH: 7.78-9.16; Temp: 22.8-26.73 OC genus. Morphological features of interest. Fusiform. Lateral bristles wide at their base, placed just Filinia longiseta (Ehrenberg, 1834) (fig. 39 a,b) underneath the corona. Two unequal caudal bris- Thriarthra longiseta Ehrenberg, 1834; tles, of variable length. Microscopic analyses of Ecology. Euplanktonic species. Inhabitant on several mastax showed this species to have 10/11 lakes, ponds, moorlands waters and brackish teeth on the uncus (Fig. 39 g). Some specimens waters. It prefers warm and eutrophic environ- had sexual eggs within their body (Fig. 39 f). ments. A filtrerer, according to Pourriot (1965) it Geographical distribution. Common in tropi- feeds mainly on particles 10 to 12 pm in size, as cal and subtropical regions. In the Iberian detritus, bacteria and algae like Chlorella, it Peninsula it has been collected from mainly probably competes with species of the genus southern reservoirs. Conochilus for food. Distribution in reservoirs. It has been found in 18 Cond: 31.5-3720 pS cm-I; Alc: 58.2-3882 localities, all in the south and in summer (Fig. 41). peq 1.'; pH: 6.3-9.9; Temp: 7.7-26.2 "C Morphological features of interest. Ventrally it Filinia terminalis (Plate, 1886) (Fig. 39 c,d) presents caudal bristles. These never are on the Thriarthra terminalis Plate, 1886. basal region. Lateral bristles are at least twice as Ecology. Euplanktonic species. Cold long as those posterior. Several varieties have stenoterm. In reservoirs it was also collected in been described: Filinia longiseta var: limnetica summer (stratification period). It probably inha- (Zacharias 1893), characterized by a proportion bits cooler waters of the hypolimnion although length of lateral bristles to length of caudal bris- this possibility could not be tested because sam- tle of more than 2. According to Carlin (1943) it ples concerned the whole water column. It has species category (Filinia limnetica). prefers mesotrophic to eutrophic conditions. However, Ruttner-Kolisko (1974) considered it Cond: 22-765.5 pS cm-'; Alc: 131-3061.5 an ecological form of E longiseta. peq 1-I; pH: 6.64-8.22; Temp: 7.3-22.8 OC

160 de Manuel, J.

Morphological features of interest. Terminal Geographical distribution. Cosmopolite, more posterior bristles on the caudal part (0 to 15 pm frequent in northern regions. It is the first record from the end of the body). Posterior bristle are for the Iberian Peninsula. almost as long as lateral ones (length of lateral Distribution in reservoirs. Identified in five bristles to length of caudal bristle is approxi- reservoirs, all of them in the northwest (Fig. 41). mately 1.2). Ruttner-Kolisko (1974) added to these characters the absence of spines on bristles Collotheca pelagica (Rousselet, 1893) (Fig. 40) (Fig. 39 c,d). In this study, as in the previous, and pelagica Rousselet, 1893; in Miracle (1976) spines could be observed on Collotheca pelagica after Harring, 1913. bristles of this species. Insertion of caudal bristle Ecology. Euplanktonic species. Typical from may be difficult to precise in preserved material large waterbodies. Warm stenoterm. It feeds on too. Koste (1980), in a revision of this genus, flagellate algae (Pourriot, 1965). Guiset (pers. proposed as a distinctive character the analysis communication) found in its digestive tract peri- of the number of teeth on the uncus: 15/16 for E dinidae (12 to 28 pm in size), Cyclotella, terminalis. Cosmarium, small flagellates and chlorococcales. Geographical distribution. Cosmopolite. In Cond: 14-3600 pS cm-'; Alk: 58.2-4681.7 Spain it is widespread. peq 1-I; pH: 6.3-9.6; Temp: 5.9-26.2 "C Distribution in reservoirs. In the 1987/88 sur- Morphological features of interest. Corona vey it was found in 14 localities. Four in summer unlobed, circular, although long cilia occur in samples, in stratified reservoirs, probably from five groups. These cilia are difficult to distinguish the hypolimnion. In the previous survey it was in fixed material. Foot is root-shaped and some- collected in 27 samples from 21 localities. times thickened. Geographical distribution. Cosmopolite. In Family COLLOTHECACEAE Spain it has only been collected in reservoirs Genus Collotheca Harring (Guiset, 1976, Telleria, 1981). Distribution in reservoirs. It is one of the most Collotheca mutabilis (Hudson, 1885) (Fig. 40 common species in Spanish reservoirs. It has been e,g; Fig. 41) collected in 40 reservoirs in summer and 52 in winter. Floscularia mutabilis Hudson, 1885; Collotheca mutabilis after Harring, 1913. BDELLOIDEA (DIGONONTA) Ecology. Euplanktonic species, in spite of the Family PHILODINIDAE fact that the genus is mainly represented by ben- Genus Scopoli thonic and sessile species. The animal is sur- rounded by a gelatinous case secreted by foot Rotaria neptunia (Ehrenberg, 1832) (Fig. 42) glands. It prefers warm water, and its occurrence Actinurus neptunius Ehrenberg, 1832; Rotifer is seasonal, i.e. it is more frequent in summer and neptunius Jennings, 1900; Rotaria neptunia, after autumn. Voigt, 1957. Cond: 19.6-154 pS cm-'; Alk: 116.8-1071.5 Ecology. Heleoplanktonic species, occurring peq 1-I; pH: 6.6-9.98; Temp: 10.7-22.3 "C occasionally in plankton. Polisaprobic, typical Morphological features of interest. Corona from eutrophic waterbodies with high alkalinity. with two lobes, one ventral and one dorsal. There It may survive low oxygen concentrations. are several long cilia on lobes, longer than the Cond: 150-655.5 pS cm-'; Alk: 1034.5-3882 cilia on the corona. These morphological charac- peq 1-I; pH: 7.5-8.8; Temp: 9.5-26.2 "C ters on the corona are difficult to appreciate in Morphological features of interest. Large, fixed material. The case is wide, with a rounded telescopic body, with a long segmented foot, end- end. Foot usually presents a spindle-shaped ing with two spurs in the last segment. In the thickening. reservoirs studied, this species has been the only

Rotifers of the Spanish reservoirs 163

ACKNOWLEDGEMENTS ARMENGOL J., J. CATALAN, N. GABELLONE, D. JAUME, J. de MANUEL, E. MARTI, J.A. My sincere thanks to the colleagues of the De- MORGUl, J. NOLLA, J. PENUELAS, M. REAL, partament d’Ecologia (Universitat de Barcelona) J.L. RIERA, S. SABATER, E SABATER & J. who participate in surveys. Specially thanks go to TOJA, 1990. A comparative limnological study of the Guadalhorce reservoirs system (Mglaga, S.E. to Montserrat Real, Eugknia Marti, Francesc Spain). Scientia gerundensis, 16 (2): 27-41. Sabater, Josep Anton Morgui, Joan Lluis Riera BARTOS, E., 1959. Rotatoria. Fauna C.S.R. 15, 1-969. and Damih Jaume. BEAUCHAMP, P. de, 1952. Un facteur de la vaiabil- I would also like to express my gratitude to it6 chez les rotifkres du genre Bruchionus. C. R. Albert Guiset for facilitating data on rotifers of Acad. Sci., Paris 234: 573-575. the previous survey of reservoirs and Joan BERZINS, B., 1962. Revision der Gattung Armengol for his unconditional support and for Anuraeopsis Lauterbom (Rotatoria). K. Fysiogra. the revision of a first draft. SEM photographs Sallsk. Lund. Forh., 32: 33-47. were taken in the Servei de Microscopia Electrd- BERZINS, B., 1978. Rotatoria. In: Limnofaum nica de la Universitat de Barcelona. Europea. J. Illies, (ed.): 54-91. G. Fisher, Stuttgart. Reservoir surveys were financed by Comission BERZINS, B. & B. Pejler, 1987. Rotifer occurrence in Assessora de Investigacih Cientifica y TCcnica relation to pH. Hydrobiologiu, 147: 107- 116. De MANUEL, J. 1991. Distribution of the (CICYT) grant PB 85-0166 and sponsored by the Brachionidae (Rotifera: Monogononta) in Spanish Direcci6n General de Obras Hidrhulicas of the reservoirs. Verh. Internat. Verein. Limnol., 24: Ministerio de Obras Publicas. 274 1-2744. De MANUEL, J. 1997. RotljCers dels embassaments espanyols peninsulars: ecologia i aspectes sis- REFERENCES tematics i zooogeografics. Tesis Doctoral. Universitat de Barcelona. AHLSTROM, E.H. 1940. A revision of the rotatorian De MANUEL, J. & D. JAUME. 1993. Zooplankton of genera Brachionus and Platyias with descriptions reservoirs from the River Ebro basin (Spain): of one new species and two new varieties. Bull. Am. Relationships with some physical, chemical and Mus. Nut. Hist., 77: 143-84. biological features. Verh. Internat. Verein. Limnol. AHLSTROM, E.H. 1943. A revision of the rotatorian 25, (2): 1236-1241 genus Keratella with descriptions of three new De MANUEL, J. & D. JAUME. 1994. Zooplankton species and five new varieties. Bull. Am. Mus. Nut. from reservoirs of the Guadalquivir river basin Hi~t.,80: 411-57. (Spain). Archiv fur Hydrobiol. Beih. Ergebn. ANSELLEM, J. & P. CLEMENT, 1980. A simplified Limnol., 40: 107-1 16. method for the preparation of rotifers for transmis- De MANUEL, J. & J. ARMENGOL. 1993. Rotifer sion and scanning electron microscopy. assemblages: a contribution to the typology of Hydrobiologia, 73: 119-122. Spanish reservoirs. Hydrobiologia, 2551256: 42 1 - AREVALO, C., 1918. Datos para els conocimiento del 428. plancton de agua duke en Barcelona. Trab. de lu De MANUEL, J., J.L. PRETUS & D. JAUME, 1992. Soc. de Biol.,: 127-131. Rotifers from the Balearic archipelago. AREVALO, C., 1923. El lago de Carucedo. Mem. de Hydrobiologia, 239: 33-41. la Real Soc. Esp. de H. N., 11 (8): 305-330. De RIDDER, M. 1962. Recherches sur les rotiferes des AREVALO, C., 1932. Investigaciones recientes en 10s eaux saumatres. VIII Quelques rotiferes des laboratorios de Polonia sobre Hidrobiologia Marismes espagnoles. Hydrobiologia, 20 (1): 92- 109. espaiiola. ReseAas cient@cas de lu Soc. Esp. de H. DONNER, J. 1970. Die Radierbestande submerser N., 6 (314): 140-143. Moose der Salzach und anderer Wasser-Biotope des ARMENGOL, J., M. ESTRADA, A. GUlSET, R. MAR- Flussbebietes. Arch. Hydrobiol. Suppl., 27: 227- GALEF, D. PLANAS, J. TOJA & F. VALLESPINOS, 324. 1975. Observaciones limnol6gicas en las lagunas de la DUMONT, H.J., 1980. Workshop on and Mancha. Bol. Est. Cent. Ecol. (Icona), 4 (8): 11-27, biogeography. Hydtohiologia, 73: 205-206. 164 de Manuel, J.

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