Introduction

The taxonomic knowledge of the spider fauna of the Dominican Republic is unique because more families are known from fossils in Miocene amber than are recorded from extant species (Penney, 1999; Penney and Pérez-Gelabert, 2002). It is also the region of the world where the fossil fauna is most similar to that of the Recent fauna. The spiders of the Dominican Republic preserved in amber are relatively well known (Penney, 2006). The Dominican amber and the extant fauna are ecologically comparable because the amber was formed in a tropical climate similar to that in the region at the present time (Penney and Pérez-Gelabert, 2002). However, apart from the pioneering works by Elizabeth Bryant (1943, 1945, 1948), the extant spider fauna of Hispaniola has not been studied in much detail (for a history of Hispaniolan araneology, see Penney and Pérez-Gelabert, 2002). During the course of a recent field trip to the Dominican Republic we had the opportunity to collect and study spiders in four areas with different habitats and elevations. In this paper we report on three spider families that were previously undiscovered for the extant fauna of Hispaniola: Ochyroceratidae, Mysmenidae, and Symphytognathidae. The ochyroceratid species is morphologically very similar to one of the species described from amber, and it is formally described here.

Ochyroceratidae is a relatively small family (146 described species in 13 genera) of small ecribellate haplogyne spiders with a cosmotropical distribution (Platnick, 2006). Although the natural history of ochyroceratids is not well known (Machado, 1951; Deeleman-Reinhold, 1995), it seems that many of them build sheet webs, sometimes with conspicuous parallel silk lines in the sheet (figs. 13B, 14D). Recently, Wunderlich (1988, 2004a) described two fossil species of Ochyroceratidae from the Dominican Republic (Arachnolithulus pygmaeus Wunderlich, 1988 and A. longipes 3637Wunderlich, 2004). To accommodate the first of these two Dominican fossil species he erected the genus Arachnolithulus Wunderlich, 1988. However, Wunderlich was uncertain as to relationships of Arachnolithulus, pointing out the need for more specimens, fossil and extant. Penney (1999) predicted extant Hispaniolan ochyroceratids (and mysmenids) based on their occurrence in the amber fauna. Alayón-García (2001) reported the presence of ochyroceratids from Navassa, a 5.2-km² island 64 km west of Hispaniola. During our fieldwork in the Dominican Republic we found a new species of Ochyroceratidae in leaf litter, in a patch of cloud forest near Paraíso (Barahona Province). This new species is morphologically similar to the extinct Dominican species Arachnolithulus longipes (known after a single male specimen in amber) and to the extant Ochyrocera thibauldi Emerit and Lopez, 1985 from the Lesser Antilles (Dominica and Guadaloupe). In this paper we describe the new species in detail and document its web architecture. Additionally, we report the presence of extant species from the araneoid families Mysmenidae and Symphytognathidae in the island for the first time. Two fossil species of Mysmenidae, Mysmenopsis lissycoleyae Penney, 2000 and Dominicanopsis grimaldii 3637Wunderlich, 2004, have been described from Dominican amber (Penney, 2000; Wunderlich, 2004b). The family Symphytognathidae had not been recorded before. Schawaller's (1981) records of eight symphytognathid specimens in Dominican amber held at the Staatliches Museum fur Naturkunde (Stuttgart, Germany) are misidentifications of theridiids (Wunderlich, 2004c: 228).

Materials and Methods

Taxonomic descriptions follow the format of Hormiga (1994, 2002). Specimens of fossil Ochyroceratidae in Dominican amber were not examined. Discussion of their relationships is based on the published text and figures. Specimens were examined and illustrated using a Leica MZ 16A stereoscopic microscope with a camera lucida. Further details were studied using a Leica DMRM compound microscope with a drawing tube. Some microscopic images were recorded using a Nikon DXM1200F digital camera and stacked using the software package Auto-Montage. A LEO 1430VP scanning electron microscope was also used to study and photograph morphological features. Left structures (e.g., palps, legs) are depicted unless otherwise stated. Hairs and macrosetae are usually not depicted in the final drawings. All morphological measurements are given in millimeters. Somatic morphology measurements were taken using a scale reticle in the dissecting microscope. Eye diameters are taken from the span of the lens. Cephalothorax length and height were measured in lateral view, and its width was taken at the widest point. Similarly, the length and height of the abdomen were measured in lateral view, and the width was taken as the widest point as seen from a dorsal view. Measurements of the abdomen are only approximations because the abdomen size changes more easily in preserved specimens than do other more sclerotized parts (e.g., the chelicerae). Total length was measured in lateral view and is also an approximation because it involves the size of the abdomen and its relative position. Approximate femur lengths were measured in lateral view, without detaching the legs from the animal, by positioning the article being measured perpendicularly. Female genitalia were excised using surgical blades or sharpened needles. Epigyna and palps were transferred to methyl salicylate (Holm, 1979) for examination under the microscope, temporarily mounted as described in Grandjean (1949) and Coddington (1983). Male palps examined with the SEM were first excised and transferred to a vial with 70% ethanol and then cleaned ultrasonically for 1–3 minutes. The specimen was then transferred to absolute ethanol and left overnight. After critical point drying, the specimens were glued to rounded aluminum rivets using an acetone solution of Acryloid B-72 and coated with gold-palladium for examination with the SEM. For SEM examination of the tracheal system, the nonchitinous abdominal tissue was digested with SIGMA Pancreatin LP 1750 enzyme complex (Alvarez-Padilla and Hormiga, in press) in a solution of sodium borate prepared following the concentrations described in Dingerkus and Uhler (1977).

Webs were photographed after dusting them with cornstarch (Eberhard, 1976) and photographed with a Nikon F100 using a 60-mm macro lens and a speedlight. All photographs have associated voucher specimens.

Taxonomy

Ochyroceratidae Fage, 1912 Ochyrocera Simon, 1891

Type Species: Ochyrocera arietina Simon, 1891 by original designation.

Composition: In addition to O. cachote, n.sp., the genus Ochyrocera includes 21 species (Platnick 2006), most of them from the Neotropical region. There are also species described from Cuba, the Lesser Antilles, including the type species, and Samoa.

Ochyrocera cachote, new species

figures 1–Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10Figure 1112

Figure 1

Ochyrocera cachote, n.sp. A, Male, dorsal. B, Male prosoma, dorsal. C, Female, dorsal. D, Female prosoma, anterior. E, Female abdomen, ventral. F, Male, left leg I, mesal.

Figure 2

Ochyrocera cachote, n.sp., male. A, Palp, mesal. B, Palp, ectal. C, Chelicera, dorsal. D, Chelicera, ventral. Scale bars 0.1 mm.

Figure 3

Ochyrocera cachote, n.sp., female. A, Tracheal system, ventral. B, Genital area. C, Chelicera, dorsal. D, Chelicera, ventral. Scale bars 0.1 mm.

Figure 4

Ochyrocera cachote, n.sp., male. A, Prosoma, dorsal. B, Prosoma, detail of cuticular surface. C, Prosoma, lateral. D, Leg I, ectal. E, Prosoma, anterior. F, Prosoma, ventral. G, Prosoma, ventral, detail of cuticular surface.

Figure 5

Ochyrocera cachote, n.sp., female. A, Prosoma, dorsal. B, Prosoma, anterior. C, Prosoma, lateral. D, Prosoma, detail of cuticular surface. E, Prosoma, ventral. F, Endites and labium (arrow, labial incision). G, Sternum, detail and cuticular sockets of macrosetae. H, Pedipalp. I, Pedipalpal claw.

Figure 6

Ochyrocera cachote, n.sp., male. A, Abdomen, ventral (arrows, from top to bottom, anterior tracheal spiracle, unidentified cuticular structure, and posterior tracheal spiracle). B, Unidentified cuticular structure. D, Detail of cuticular surface and setal socket. D, Posterior tracheal spiracle.

Figure 7

Ochyrocera cachote, n.sp. A, Female, abdomen, lateral (top arrow, pit; bottom arrow, posterior tracheal spiracle). B, Male, abdomen, lateral. C, Detail of female abdominal pit. D, Female, posterior tracheal spiracle. E, Female, spinnerets, lateral. F, Male, spinnerets, lateral.

Figure 8

Ochyrocera cachote, n.sp., male palp. A, Mesoventral. B, Ectal. C, ventral. D, Cymbium, apical (arrow, tarsal organ). E, Tegulum and embolus, ectal. F, Cymbial process and cuspule. G, Tarsal organ. H, Embolus, apical region.

Figure 9

Ochyrocera cachote, n.sp., male spinning organs. A, Spinnerets and colulus. B, PLS. C, ALS. D, PMS. E, PLS, lateral. F, Epiandrous fusules.

Figure 10

Ochyrocera cachote, n.sp., Female spinnerets. A, Spinnerets and colulus. B, PLS. C, PMS. D, PLS, detail of aciniform spigots. E, ALS. F, PLS, lateral.

Figure 11

Ochyrocera cachote n.sp., male tracheal system. A, Ventral. B, Anterior tracheae. C, Detail of anterior tracheae.

Figure 12

Ochyrocera cachote, n.sp., male tracheal system. A, Base of posterior tracheal trunks. B, Detail of base of posterior tracheal trunk. C, Detail of posterior tracheal trunks and tracheoles. D, Detail of apical region of anterior tracheoles.

Figure 13

Ochyrocera cachote, n.sp., web architecture (cloud forest in Barahona Province, Paraíso, Reserva Natural Cachote). A, Web in leaf litter. B, C, Details of web showing silk lines running in parallel to each other, probably made of silk from the linearly arranged brush of PLS aciniform gland spigots (all webs dusted with cornstarch). Photos by Gustavo Hormiga.

Figure 14

Ochyroceratid webs. A–C, Ochyrocera cachote, n.sp., webs from a cloud forest in Barahona Province, Reserva Natural Cachote. D, Web of an unidentified ochyroceratid from Thailand (Chiang Mai, Doi Inthanon National Park, photo GH36/R02 03.X.2003) showing a similar arrangement of silk lines running in parallel to each other. Photos by Gustavo Hormiga.

Type

Male holotype and female paratype from Barahona Province, Paraíso, Reserva Natural Cachote, cloud forest surrounded by secondary growth, N 18°05′54.8″: W 71°11′22.0″, 1220 m, 6–9.IV.2005, G. Hormiga, F. Alvarez-Padilla, and S.P. Benjamin (deposited in MCZ).

Etymology

The species epithet is a noun in apposition taken from the type locality.

Diagnosis

Males of Ochyrocera cachote, n.sp. can be distinguished from other species of Ochyrocera by the absence of a clypeal apophysis (fig. 1B) and the details of the cheliceral teeth (fig. 2C, D), including the presence of a large tooth toward the base of the cheliceral furrow. The cymbial apophysis and the embolus shape (figs. 2A, B, 8A–C) are also diagnostic. The lack of a monographic treatment of Ochyrocera and the absence of detailed and uniform descriptions of the species currently placed in the genus make it impossible to accurately diagnose females. Most likely the shape of the spermathecae (fig. 3B) combined with the cheliceral teeth (fig. 3C, D) are unique for this species.

Description

Male (holotype): Total length 2.83. Cephalothorax 1.09 long, 0.89 wide, 0.31 high. Sternum 0.59 long, 0.61 wide. Abdomen 1.74 long, 0.6 wide, 0.65 high. Specimens in alcohol have general bluish appearance. Cephalothorax bluish yellow with two light longitudinal bands running in parallel from clypeus through posterior carapace margin (fig. 1A, B). Chelicerae yellowish, fangs red brown. Six eyes in three groups; eyes slightly elevated, with black rings. AME diameter 0.09, 0.3 times one AME diameter away from ALE. Clypeus height 0.29, projecting forward, with two pairs of setae, with ectal pair longer and more robust than distal pair (fig. 4A, C, E). Sternum yellowish with dark lateral margin, seven macrosetae in three rows of 3, 2, 2 setae each; ectal setae longer and more robust than distal setae. Endites with several macrosetae. Labial anterior margin notched (fig. 4F). Legs yellowish with black blotches, no apparent pattern; tarsi with cuticular folds and pigmentation pattern (fig. 1F) that gives appearance of pseudosegmentation. Leg formula 1432. Femur I 4.03 long, 3.7 times length of cephalothorax. Chelicerae anteriorly protruding with prominent single promarginal tooth flanked distally by two small teeth and basally by six small teeth (figs. 1A, B, 2C, D, 4E). Palp (figs. 1A, B, 8A–H): tibia long and cylindrical (ca. 3.6 times its diameter), with two dorsal, two mesal, two ectal trichobothria; cymbium conical, 0.66 the palpal tibia length, with long ectal digitiform apophysis carrying a cuspule at its apical end; tegulum ovoid, tapering to pointed end; sperm duct diameter tapering from reniform fundus (located at tegulum cymbium joint) toward opening, with one switchback loop; embolus ribbonlike, tapering toward the end and oriented perpendicularly to longitudinal axis of tegulum. Tarsal organ fusiform, apical region divided into three points (fig. 4G). Epiandrous fusules: (fig. 9F) six fusules with globular base linearly arranged in anterior margin of circular depression anterior to epigastric furrow. Spinnerets (fig. 9A–E): colulus fleshy and long (fig. 9A); ALS with one major ampullate gland spigot accompanied by nubbin and seven piriform spigots (fig. 9C); PMS with a single spigot, probably a minor ampullate (fig. 9D); PLS has tightly packed row of 26 aciniform gland spigots with very long bases (fig. 9B, E).

Female (paratype): Total length 2.45. Cephalothorax 0.81 long, 0.7 wide. Sternum 0.43 long, 0.48 wide. Abdomen 1.64 long, 0.81 wide. Coloration and markings as in male, although females seem slightly darker than males (fig. 1C–E). Six eyes in three groups; slightly elevated, with black rings. AME diameter 0.06, 0.3 times one AME diameter away from ALE. Clypeus height 0.22, projecting forward, with two pairs of setae, ectal pair longer and more robust than distal pair (fig. 5A–C). Sternum coloration as in male, labial anterior margin notched (fig. 5F). Pedipalpal tarsal claw a small conical structure (fig. 5I). Legs yellowish with black blotches, no apparent pattern. Pseudosegmentation present but less apparent than in males. Leg formula 1423. Femur I 2.03 long, 2.5 times length of cephalothorax. Chelicerae with eight small teeth (fig. 3C, D). Vulva (fig. 3B) provided with pair of elongated spermathecae, lightly sclerotized; sclerotized structure of uncertain nature seen between the spermathecae. Spinnerets (fig. 10A–F): colulus, fleshy and long (fig. 7A); ALS with one major ampullate gland spigot accompanied by nubbin and seven piriform spigots (fig. 10E); PMS with single spigot, probably minor ampullate (fig. 10C); PLS has tightly packed row of 23 aciniform gland spigots with very long bases (fig. 10A, B, D, F).

Tracheal system (figs. 3A, 7A, D, 11A–C, 12A–D; description is based on single male and female specimen dissection due to paucity of study material): booklungs modified into tracheae that open through anterior spiracles. In male, anterior tracheal system consists of two bundles of three short tracheae confined to abdomen plus leaflike trachea of about half length of other three tracheae (fig. 11A–C). Female anterior tracheal system very similar but lacks leaflike tracheae (fig. 3A). Posterior tracheal system consists of pair of tracheal bundles that open to small atrium (figs. 3A, 11A–C, 12A–D). Each bundle has four anteriorly directed tracheae that enter prosoma. In the male at least some of those tracheae divide into smaller tracheoles. Female specimen had tracheae broken off in area near pedicel (fig. 11A); their diameter suggests that these tracheae continue into prosoma through pedicel. In female, one of four tracheae of each anteriorly directed bundle branches into smaller tracheoles (fig. 12C). In addition, each bundle has a pair of smaller tracheae (both in diameter and length) that branches into multiple tracheoles. Posterior tracheal spiracle positioned approximately halfway between colulus and epigastric furrow (fig. 10A).

Natural History

Ochyrocera cachote, n.sp. was collected in the leaf litter and in small cavities in the ground in Dominican cloud forests at ca. 940–1200 m of elevation. They build small and rather flimsy three-dimensional sheet webs with silk lines extending above the sheet (figs. 13A–C, 14A–C). The sheet appears to be of structural lines overlaid with finer silk lines running parallel to each other, probably made of silk from the linearly arranged brush of PLS aciniform gland spigots (fig. 7A, B, E, F).

Additional Specimens Examined

Dominican Republic: Barahona Province, Paraíso, Reserva Natural Cachote, cloud forest surrounded by secondary growth, N18°05′54.8″: W71°11′22.0″, 1220 m, 6–9.IV.2005, G. Hormiga, F. Alvarez-Padilla, and S.P. Benjamin, 4 males, 7 females (MCZ). Duarte Province, San Francisco de Macorís, Reserva Científica Loma Quita Espuela, cloud forest to tower, N19°21′00.6″: W70°08′31.0″, 942 m, 19–21.IV.2005. F Alvarez-Padilla and S.P. Benjamin, 2 males, 3 females (MCZ).

Other New Family Records for Hispaniola

Family Mysmenidae

Microdipoena sp.

This species was collected in two localities: a sinkhole in the Cueva del Puente (Parque Nacional del Este–Guaraguao) and in a cloud forest in the Duarte Province. Cueva del Puente, in the eastern region of the island, close to sea level (ca. 50 m of elevation), is located in a coastal area covered with dry forest. The sinkhole area of the cave has shrubby vegetation and higher humidity than does the corresponding epigean area. The spiders built typical “egg-shaped” webs (fig. 15C, D) in crevices among rocks on the ground. In the cloud forest we found Microdipoena sp. webs in the leaf litter.

Figure 15

Webs of Dominican Republic symphytognathids and mysmenids. A, B, Web of Patu sp. (Symphytognathidae), cloud forest in Barahona Province, Paraíso, (Reserva Natural Cachote). C, D, Web of Microdipoena sp. (Mysmenidae), cloud forest in Duarte Province, San Francisco de Macorís (Reserva Científica Loma Quita Espuela). Photos by Gustavo Hormiga (A, B) and Fernando Alvarez-Padilla (C, D).

Material Examined

Dominican Republic: La Altagracia Province, Guaraguao, Parque Nacional del Este, Cueva del Puente, N18°20′25.4″: W 68°48′55.8″, 5 m, 2.IV.2005, G. Hormiga, F. Alvarez-Padilla, and S.P. Benjamin (1 male, 1 female). Duarte Province, San Francisco de Macorís, Reserva Científica Loma Quita Espuela,¸ F. Alvarez-Padilla and S.P. Benjamin, photos 7646–7652 FAP (20.IV.2005, 1 female) (deposited in MCZ).

Family Symphytognathidae

Patu sp.

Webs of this species were common in the leaf litter in a cloud forest of the southwestern region of the country (fig. 15A, B). The web was a horizontal planar orb web with numerous radii (including many accessory radii) and without out-of-plane radii in the finished webs, as is typical of this family (e.g., Griswold et al., 1998: fig. 3C). The spider is often found upside-down at the hub.

Material Examined: Dominican Republic: Barahona Province, Paraíso, Reserva Natural Cachote, cloud forest surrounded by secondary growth, N18°05′54.8″: W71°11′22.0″, 1220 m, 6–9.IV.2005, G. Hormiga, F. Alvarez-Padilla, and S.P. Benjamin (males and females): photos 9–11/R1 GH (7.IV.2005, 1 female); photos 12–15/R3 GH (9.IV.2005, 1 female); photos 16–26/R3 GH (9.IV.2005, 1 female); photos 7364–7366 FAP (1 female; deposited in MCZ).

Symphytognatha sp.

Material Examined: Dominican Republic: Barahona Province, Paraíso, Reserva Natural Cachote, cloud forest surrounded by secondary growth, N18°05′54.8″: W71°11′22.0″, 1220 m, 6–9.IV.2005, G. Hormiga, F. Alvarez-Padilla, and S.P. Benjamin (1 female; deposited in MCZ).

Discussion

Ochyroceratids, mysmenids, and symphytognathids are common inhabitants in humid soil microhabitats of the Neotropical region. From a faunistic and taxonomic point of view, the discovery of these three spider families in the Dominican Republic is hardly surprising and, as mentioned above, the presence of the first two families had already been predicted based on the study of Dominican amber. Similarly, we agree with Penney (1999) in predicting that future work will document the presence in the island of the araneoid family Anapidae, so far known only from a fossil species (Palaeoanapis nana Wunderlich, 1988). Brignoli (1983) had suggested that the linyphiid species Lomaita darlingtoni Bryant, 1948, described from Hispaniola, was misplaced and that it could be a mysmenid. Examination of the type material of L. darlingtoni (Miller, 2003) and of specimens recently collected by us in the Dominican Republic confirms its correct placement in Linyphiidae.

Our findings confirm Penney's prediction (1999) and highlight the paucity of data on the extant spider fauna of Hispaniola (see Platnick and Penney [2004] and Rheims and Brescovit [2004] for other recent new family records). There has been very little systematic research on the extant spider fauna of the island during the last half-century, which seems rather ironic given the many studies published during the last two decades on the spiders fossilized in Dominican amber.

The systematics of the family Ochyroceratidae remains poorly studied, and generic circumscriptions are often ambiguous. Although the family lacks a global phylogenetic revision, it seems clear that a significant fraction of its diversity remains undescribed. This latter point is well illustrated by Deeleman-Reinhold's (1995) recent taxonomic study of the Indo-Pacific region ochyroceratid fauna: not surprisingly most of the species treated are new. The absence of explicit phylogenetic definitions of ochyroceratid genera considerably complicates the assignment of this new Dominican species to a genus. As mentioned earlier, this new species is morphologically similar to the extinct Dominican species Arachnolithulus longipes and to the extant Ochyrocera thibauldi. It is unclear why Wunderlich (2004a) placed Arachnolithulus longipes in the genus Arachnolithulus, because the male palp morphology of the type species (A. pygmaeus) is rather different from that of A. longipes. The male palps of Fageicera cubana Dumitrescu and Georgescu, 1992 (the type species of Fageicera) and O. cachote, n.sp. are also very similar in having both a long and thin cymbial process with a cuspule at the end (compare fig. 10B to Dumitrescu and Georgescu, 1992: fig. 5). The type species of Ochyrocera (O. arietina Simon, 1891), from Cuba and St. Vincent (Lesser Antilles), also has a cuspule in the apical region of the cymbium. The morphology of the epiandrous fusules of O. cachote, n.sp. (fig. 9F) is similar to that reported for other members of the genus, namely O. thibauldi (Emerit and Lopez, 1985: fig. 1B) and O. caeruleoamethystina Lopez and Lopez, 1997 (Lopez and Lopez, 1997: fig. 27). It consists of six fusules in a circular depression, linearly arranged anterior to the epigastric furrow (there are five in O. thibauldi and six in O. caeruleoamethystina). It is under these circumstances that we have hypothesized that O. cachote, n.sp. is congeneric with the type species of Ochyrocera. Future revisionary and monographic work will test this conjecture.

Very little is known about the natural history and biology of ochyroceratids, and most of what is known about them can be found in just a few references, such as the works of Machado (1951, 1964) and Deeleman-Reinhold (1995). The web of O. cachote, n.sp. (figs. 13A–C, 14A–C) is similar to the webs of other ochyroceratids (Hormiga, unpubl.). A similar architectural pattern of parallel silk lines can be found in other ochyroceratids, such as the species from Thailand that we illustrate for comparative purposes (fig. 14D). Although very little has been published about ochyroceratid web architecture, the presence of linearly arranged PLS spigots in other species (e.g., Machado, 1951) predicts that the study of their webs may reveal similarly arranged silk lines running parallel to each other. Such parallel silk lines add a sense of “order” generally not found in non-orb webs.

Web architecture is often informative at some hierarchical level, usually above the species level (Eberhard, 1990). Web architecture has been considered to be directly linked to the spider's behavior and not to the arrangement of spinneret spigots (Benjamin and Zschokke, 2003). For example, the highly ordered patterns found in orb webs are considered to be mostly the result of stereotyped web building behaviors (Eberhard, 1982; Benjamin and Zschokke, 2004). Spiders with very similar spinneret spigot morphology can build conspicuously different webs. Although we do not have data on the web-building behavior of O. cachote, the pattern of silk lines running parallel to each other is consistent with the conjecture that it has been produced by the PLS with its linearly arranged spigots. This is the first reported case where apparent order or pattern in the web architecture seems to be generated by the arrangement of spinneret spigots instead of the spider behavior.