This paper describes and provides information on the species of the genus Conus (Neogastropoda:Conidae) preserved in the Laboratorio de Biología y Sistemática de Invertebrados Marinos de la Facultad de Ciencias Biológicas (LaBSIM) y el Museo de Historia Natural de la Universidad Nacional de San Marcos (MUSM). The material was collected at the Department of Tumbes (9 locations) and Piura (16 locations). Intesive collect was realized in April 2007 and occasional in posterior years. Of the 16 reported species it is counted with material corresponding to 11 of them: Conus (Conus) gladiator Broderip, 1833; Conus (Asprella) arcuatus Broderip & Sowerby, 1829; Conus (Cylinder) lucidus Wood, 1828; Conus (Leptoconus) poormani Berry, 1968; Conus (L.) recurvus Broderip, 1833; Conus (Pyruconus) fergusoni ;Sowerby, 1873; Conus (P.) patricius Hinds, 1843; Conus (Ximeniconus) mahogani Reeve,1843;...

The following species of Gastropoda are recorded for the first time for Peruvian waters: Sthenorytis turbinus Dall, 1908, Crucibulum (Crucibulum) umbrella (Deshayes, 1830), Favartia (Murexiella) lappa (Broderip,1833), Cantharus (Cantharus) shaskyi Berry, 1959, Cantharus (Solenosteira) macrospira (Berry, 1957), Cancellaria (Bivetopsia) haemastoma Sowerby, 1832.

The following species of Bivalvia are recorded for the first time for Peruvian sea: Ennucula panamina (Dall, 1908), Nuculana (Nuculana) loshka, (Dall,1908), Saccella laeviradius (Pilsbry & Lowe, 1932), Liralucina approximata (Dall, 1901), Carditamera radiata (G. B. Sowerby I, 1833), Carditella (Carditella) naviformis (Reeve, 1843); Macoma (Psammacoma) elytrum Keen, 1958, Psammotreta (Psammotreta) pura (Gould, 1853), Sphenia fragilis (H. Adams & A. Adams, 1854) y Caryocorbula amethystina Olsson, 1961. Se informa sobre la distribución, el hábitat y comentarios relevantes sobre cada una de las especies.

Seis especies de Bivalvia: Adrana sowerbyana (Orbigny, 1845); Malletia goniura Dall, 1890; Mytilus strigatus Hanley, 1843; Leiosolenus spatiosa (Carpenter, 1857); Pinna rugosa G.B. Sowerby I, 1835 y Delectopecten zacae (Hertlein, 1935) se reportan por primera vez para aguas peruanas. Se da información sobre la distribución, el hábitat y comentarios relevantes de cada una de las especies.

Cinco especies de gasterópodos: Northia pristis (Deshayes in Lamarck, 1844), Macron aethiops (Reeve, 1847), Latirus concentricus (Reeve, 1847), Terebra elata, Hinds, 1844 y Carinodrilla adonis Pilsbry & Lowe, 1932, se reportan por primera vez para aguas tropicales del mar peruano. Se da información sobre la distribución, el hábitat y comentarios relevantes sobre cada una de las especies.

The star sea Henricia obesa (Sladen, 1889) (Asteroidea: Echinasteridae) is reported for the first time from Peruvian sea.

In the present work the taxonomic of the family Calyptraeidae Lamarck, 1809 in the Peruvian coast are reviewed. The presence of 17 species of the 19 is confirmed reported by diverse authors. Crepidula arenata (Broderip, 1834) is synonymous of C. excavata (Broderip, 1834). Information on the distribution geographical and same relations ecological is presented.

We report 8 species of Ellobiidae from the Peruvian coast, which belong to the subfamilies Ellobiinae: Ellobium stagnale (Orbigny, 1835) and Sarnia frumentum Petit, 1842; Melampodinae: Melampus carolianus (Lesson, 1842), Melampus olivaceus Carpenter, 18574 and Detracia graminea Morrison, 1846; and Pedipedinae: Marinula acuta (Orbigny, 1835), Marinula concinna (C.B Adams, 1852) and Marinula pepita King, 1831. Six species live associated to the mangrove of the department of Tumbes, and two in boulder beaches in the limits of the Peruvian Province. Four tropical species are registered for the first time in the Peruvian Sea: A. stagnale, M. olivaceus, D. graminea and M. acuta.

The incursion of 25 tropical species of mollusks and 15 of crustaceans have been analyzed. This species were registered among the years 1972 and 2003, time in which five El Niño events (EN) were occurred. Presence of the tropical species in the Peruvian Province would be related to larvae transport for benthonic species and juvenile for pelagic species, both stimulated by movements of the masses of waters. It is possible that some species have found «refuge areas» where to be developed and to remain, these species would display a discontinuous distribution in the Peruvian Province, like it is the case of Malea ringens, Prunum curtum and Bulla punctulata. Other species that intrude when typical oceanographic conditions of an event appear EN, apparently disappear when recovering the conditions «No Nino».

The following species of marine bivalve mollusks were recorded for the first time from the Peruvian sea: Glycymeris (Axinactus) delessertii (Reeve, 1843); Botula cylista Berry, 1959; Parahyotissa (Pliohyotissa) quercinus (Sowerby II, 1871); Pitar (Pitar) helenae Olsson, 1961; Eurhomalea lenticularis (Sowerby I, 1835); and Cardiomya planetica (Dall, 1908). Description, habitat and the geographical distribution are cited for each species.

Six bivalve species: Thyasira flexuosa (Montagu, 1803); Diplodontina tumbesiana Stempell, 1899; Retrotapes exalbidus (Dillwyn, 1817); Pandora (Pandorella) cornuta C.B. Adams, 1852; Entodesma cuneatum (Gray, 1828); Periploma (Cricoploma) carpenteri Dall, 1896 are the first time reported for Peruvian sea. Distribution, habitat and relevant observations of each one species are included.

The following species of Bivalvia have been recorded for the first time for Peruvian waters: Nucula (Nucula) iphigenia (Dall, 1908); Ennucula cardara (Dall, 1916); Nuculana (Nuculana) extenuata (Dall, 1897); Orthoyoldia panamensis (Dall, 1908). These bivalves were collected in the platform and continental slope down to depths of 864 meters.

Four species of marine bivalve mollusks, Nuculana (Jupiteria) cuneata (Sowerby, 1833), Isognomon (Isognomon) janus Carpenter, 1857, Ostrea conchaphila Carpenter, 1857 and Mysella (Rochefortia) molinae Ramorino, 1968 are reported for the first time from Peruvian sea. Data are included on the geographical distribution and habitat of each species.

The present state of knowledge on the aquatic mollusks of Peru is reviewed herein. Marine and freshwater mollusks are treated separately, offering information on numbers of families, genera and known species, their geographical distribution, their conservation status and utilization by man. Updated species lists are included.

The faunistic diversity of the rocky intertidal zone of the Department of Lima, Perú, was studied in sixteen localities with emphasis in the relative dominance of the species and its vertical distribution. 175 species of invertebrates are registered, predominating the mollusks (79 species), crustaceans (44 species) and polychaete (30 species), the three taxa that predominate in the benthos marine. Considering the communities studied 41% for Perumytilus purpuratus are registered, 34% in Semimytilus algosus and 50% of the species for Phragmatopoma moerchi. Diversity and zonation are generalized for the Peruvian Province.

Five species of marine gastropods are reported for the first time from Peru: Crepidula nivea Lamarck, 1799, Neosimnia aequalis (Sowerby, 1832), Simnialena rufa (Sowerby, 1832), Nitidiscala elenense (Sowerby, 1844) and Trigonostoma (Ventrilia) bullatum (Sowerby, 1832). Data on habitat and geographical distribution of any one of the species reported is included.

The discovery of mollusks that normally are distributed in the boundaries of Panamanian Province in many localities of the Peruvian Province between years 1972 and 1994, period in which several events appeared "El Niño". Fifteen species of mollusks was possible determine, that extend own distribution: Pteria sterna, Orobitella peruviana, Cryptomya califórnica, Cerithium (T) stercusmuscarum, Malea ringens, Hexaplex brassica, Thais styllmanberryi, T. (M.) triangularis, T. (T.) callaoensis, Acanthina brevidentata, Purpura pansa, Neorapana muricata, Anachis (C.) nigricans, Cancellaria (C.) decussata and C. (B.) chrysostoma. Variability in the boundaries of the biogeographics provinces of the Peruvian Coast, controlled by the ENSO, has been postuled.

This paper deal with seven species of Acmaeidae Scurria viridula (Lamarck), S. parasitica (Orbigny), S. variabilis (Sowerby), S. zebrina (Lesson), Collisella orbignyi (Dall), C. ceciliana (Orbigny) and C. araucana (Orbigny) reported along the rocky along Lima Department. Information concerned with geographical and vertical distribution, and others ecological data are also added.

Thirty-four samples of mussel assemblages were studied in the rocky mid-littoral zone at 10°45'38"S - 12°57'39"S, in the department of Lima, Peru. Such samples were taken periodically, between June and November, 1972. Using the biological index method, two kinds of communities were determined for the area: community of Perumytilus purpuratus (Lamarck, 1819), in the mid-horizon of the mid-littoral zone and community of Semimytilus algosus (Gould, 1850), in the lower horizon of the mid-littoral zone.

In the present paper the species of Donax Linnaeus, 1758 in Peru are reviewed. The presence of 7 out of the 11 species is confirmed: D. asper Hanley. 1845; D. caelatus rothi Coan, 1983; D. obesulus Reeve, 1854; D. carinatus Hanley, 1843; D. transversus Sowerby 1,1825; D. californicus Conrad, 1837 and D. marincovichi Coan, 1983; in addition, one is recorded for the first time (D. punctatostriatus Hanley, 1843) in Peruvian waters. Information on the distribution geographical and some ecological relations is presented.