Inventory of the Echinodermata collection from the Universidade Federal de Alagoas. Collections and inventories provide important and essential information for understanding the composition and distribution of biodiversity. The collections were made over a period of more than 20 years, at several localities of coastal Alagoas. This collection now includes 16, catalogued individual specimens, with 50 species in the five extant classes Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea, based on records; the class Ophiuroidea is best represented. The results of this inventory contribute significantly to knowledge of marine benthic diversity from the state of Alagoas, and the information presented here expands the data for Echinodermata from the northeastern coast of Brazil. Keywords: biodiversity, echinoderm, taxonomy, benthic macroinvertebrate, Brazil.
|Published (Last):||18 November 2008|
|PDF File Size:||10.36 Mb|
|ePub File Size:||9.80 Mb|
|Price:||Free* [*Free Regsitration Required]|
A total of 64 specimens were analyzed and identified into 12 species, belonging to 11 genera, eight families and three classes. Brief taxonomic descriptions, figures and ecological notes for recorded species are provided. Ophiuroidea and Holothuroidea were the most representative taxa.
Biogenic structures are an important habitat for young specimens and some small species of Echinodermata. Some species complete their life cycle in these structures, while others spend part of their life in these substrates and may also migrate to other habitats. The work complements the knowledge of echinoderm biodiversity from Northeastern of Brazil and aims to support future projects of protection and sustainable management of this area. As amostras foram coletadas ao longo de um ano a partir de rodolitos.
Ophiuroidea e Holothuroidea foram os grupos mais representativos. Rhodoliths are aggregates of nodules of unarticulated encrusting coralline algae Amado-Filho et al.
These structures occur in shallow waters up to depths of m, forming extensive rhodolith beds and hard bottom habitats. These rhodoliths provide refuge, food and other resources, protecting organisms from competitive exclusion, predation, and physical disturbance Riul et al.
The Seixas Beach has a large bank of rhodoliths susceptible to degradation by anthropogenic impact, in the form of tourism and commercial exploitation. Echinoderms can be found in various substrata. Small species and young specimens usually live associated with coral reefs, rhodolith beds, and algae. These animals are exclusively marine and belong to the benthic fauna, with many species inhabiting rocky shores, beaches, bays and subtidal zones, including the deep-sea Pawson The phylum consists of approximately 7, living species and 13, extinct species, comprising the classes Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea Pawson According to Ventura et al.
In part, this is due to the lack of reliable information on taxonomy and distribution ranges. About species of Echinodermata are recorded along the Brazilian coast Ventura et al. Here, we list the species of echinoderms found associated with rhodoliths from the Seixas Beach, followed by brief descriptions, ecological notes for species, and a discussion on the importance of this habitat for young and small species of echinoderms.
The climate is tropical and humid, with a conspicuous seasonal pattern of rainfall. The rainy season goes from March to August, and the dry season extends from September to February.
Around this rhodolith formation, water depths vary from 0. The deeper portions vary from 3. Figure 1 indicates collecting locations at the Seixas Beach PB. Expeditions were conducted in the infralittoral of the Seixas Beach.
Small boats were used to access to the reef environment. Collecting location were positioned at depths of 1. Geographical coordinates of each collecting site were recorded with a GPS. The depth of 1. Collections were made in January, March, May, July, September and November, during the lowest tides along the year of Samples were replicated each month, totaling 12 samples in the year.
Specimens were collected manually, with the help of a square of 15 X 15 cm, within which rhodoliths were collected. In the lab, samples were maintained separate in trays with sea water, with salinity at 35 ppm and continuously aerated, up to the time of processing of the material with a hammer and stylets.
Taxonomic identifications were based on Tommasi , Hendler et al. Measurements were obtained from fixed specimens. A total of 62 individuals were recorded from inside rhodoliths, belonging to three classes, four orders, eight families, 11 genera and 12 species of echinoderms, as listed below.
Scales: a-d, f, 1 mm; e, 0. The arms are oriented from the distal to proximal region. Amphipholis squamata — Albuquerque, : , fig. V, fig. Material examined: 5 specimens UFPB. Description: Disk rounded, covered by medium size scales, with circular to semicircular imbricated scales Figure 2a , 2b.
Primary scales large, easily observed Figure 2c. Radial shields slightly long than wider, separated by a thin scale up to the distal region of the shields. Ventral surface of the disk covered by scales similar to dorsal scales Figure 2d. Bursal slits narrow, near the first plate of the arms. Diamond-shaped oral shield, adoral shields longer than wide, touching the proximal edge.
Two oral papillae in each side of jaw, the more distal bigger and trapezoidal, other rounded and smaller. A pair of elongated infradental papillae Figure 2e. Five arms, about five times the disk diameter. Dorsal arm plate slightly pentagonal, with distal edge rounded Figure 2f.
Ventral arm plate pentagonal, two tentacular scales Figure 2g. Lateral arm plates meeting in the longitudinal mid-line, with four arm spines Figure 2h.
Color white. The species occurs from shallow waters to m depth Pawson et al. Ecological notes: The specimens were found inside rhodoliths but can be buried in crevices, sand and coral rocks. Scales: a-b, 10 mm; c-d, f-h, 2 mm; e, 1 mm.
Amphipholis januarii — Tommasi, : 1, fig. Material examined: 16 specimens UFPB. Description: Disk circular to pentagonal, with reentrances in inter-radial areas Figure 3a. Disk covered by small and imbricated scales. Radial shields narrow, longer than wide, usually separated by one or two scales, the internal more elongated Figure 3c. Ventral side of the disk covered by smaller scales, imbricated Figure 3d.
Bursal slit long, near the first arm plate. Oral shield diamond-shaped, adoral shield triangular. Two oral papillae in each side of jaw, the distal triangular and robust, a pair of elongated and robust infradental papillae Figure 3e. Five elongated arms, about seven to ten times the diameter of the disk Figure 3b. Arms tapering distally.
Dorsal arm plate wider than long Figure 3f , ventral arm plate pentagonal Figure 3g , with rounded edges. Two tentacle scales, small and flattened. Lateral arm plate with three to four elongated spines, similar in size Figure 3h. The arm spine of middle with one or two teeth at the apex. Color white to yellow. From 1 to m depth Laguarda-Figueras et al. Ecological notes: This species usually is found in sand bottom and gravel Tommasi , algae, under rocks Hendler et al. Scales: a-b, 5 mm; c, 1 mm; d-h, 2 mm.
Micropholis gracillima — Tommasi, : 39, figs. Material examined: 3 specimens UFPB. Description: Disk rounded with indentations in the radial region Figure 4a. Disk covered by numerous small and imbricated scales. Radial shields narrow and elongated, joined at half of length, and then separated by three scales on the proximal edge Figure 4c.
Ventral surface of disk covered by small and imbricated scales. Bursal slit large, near the first to fourth ventral arm plate Figure 4d. Oral shield diamond-shaped. Adoral shield elongated and slightly wide distally. Jaws with three oral papillae, the more distal rectangular, bigger than proximal papilla. Arms long, about six to eight times the diameter of the disk Figure 4b. Dorsal arm plate trapezoidal Figure 4f.
Ventral arm plate square-shaped, with distal edge rounded Figure 4g. Two tentacle scales, the most internal robust. Lateral arm plate with four arm spines Figure 4h.
Second arm spine near the ventral arm plate, with small teeth. Color light brown to yellowish. From intertidal zone to 26 m depth Hendler et al. Ecological notes: This species is usually found in soft bottom Tommasi , with intermediate granulometry and high organic content Zimmerman Scales: a-b, 5 mm; c-g, 1 mm. Ophiactis savignyi — Brito, a : 4, fig. Material examined: 1 specimen UFPB.