Ariidae Bleeker

Alexandre P. Marceniuk & Naércio A. Menezes, 2007, Systematics of the family Ariidae (Ostariophysi, Siluriformes), with a redefinition of the genera., Zootaxa (1416), pp. 1-126 : 111-121

[[ Family Ariidae Bleeker ]]

Identification key to genera

This key is based on the use of external morphological characters allowing for the identification of taxa without the need of osteological preparations. Being artificial, it has to be used from its beginning since generic identification can be reached through different entries.

1. Maxillary barbel present ............................................................................................................................ 2

- Maxillary barbel absent .................................................................................................. Batrachocephalus

2. Mental barbels present; maxillary barbel soft, fleshy along its entire length ............................................ 3

- Mental barbels absent; maxillary barbel hard, bony along its entire length ....................... Osteogeneiosus

3. Two pairs of mental barbels; maxillary barbel cylindrical ........................................................................ 4

- A single pair of mental barbels; maxillary barbel compressed, tape-like ........................................... Bagre

4. Cephalic shield clearly exposed, ornamented with grooves, ridges and granules, covered by a very thin layer of skin; anterior and median nuchal plates indistinct; posterior cleithral process and second dorsal process of cleithrum distinct and pointed .................................................................................................. 5

- Cephalic shield only slightly exposed, covered by musculature and thick skin; anterior and median nuchal plates conspicuous; posterior cleithral process and second dorsal process of cleithrum connected by a bony blade ................................................................................................................................. Galeichthys

5. Premaxillary and dentary with several rows of conical, viliform or molar-like teeth ............................... 6

- Premaxillary and dentary teeth with a single row of incisiform teeth .......................................... Ketengus

6. Adipose fin long, its base as long as anal-fin base .................................................................................... 7

- Adipose fin moderately long or short, its base no longer than one-half the length of anal-fin base ................................. 13

7. Anterior and median nuchal plates very reduced, forming a structure of semi-lunar aspect; posterior margin of occipital process concave; occipital process triangular shaped, moderately long and wide; accessory tooth plates bearing small conical teeth..................................................................................................... 8

- Anterior and median nuchal plates very large, square to pentagonal shaped; posterior margin of occipital process convex; occipital process round, very short and wide at base; accessory tooth plates large, bearing molar-like teeth ............................................................................................................................... Aspistor

8. Tooth plates associated with vomer present .............................................................................................. 9

- Tooth plates associated with vomer absent.............................................................................................. 10

9. Posterior cleithral process very short; accessory tooth plates transversely elongated and narrow............... ..................................................................................................................................................... Hemiarius

- Posterior cleithral process moderately long; accessory tooth plates large, triangular, oval or round........... ........................................................................................................................................................ Notarius

10. Posterior cleithral process very long; posterior cranial fontanel long and narrow .................................. 11

- Posterior cleithral process short or moderately long; posterior cranial fontanel wide and oval.............. 12

11. Accessory tooth plates present..................................................................................................... Cinetodus

- Accessory tooth plates absent....................................................................................................... Pachyula

12. Fenestra limited by supraoccipital, pterotic and sphenotic present; posterior cranial fontanel very large; posterior cleithral process very short.................................................................................... Cephalocassis

- Fenestra limited by supraoccipital, pterotic and sphenotic absent; posterior cranial fontanel large; posterior cleithral process moderately long ....................................................................................... Amphiarius

13. Accessory tooth plates bearing large molar-like teeth............................................................................. 14

- Teeth of the accessory tooth plates small or absent, when present conical or viliform ........................... 16

14. Adipose fin very short, its base less than one-half length of anal-fin base; medial groove of neurocranium limited by frontal bones and also on supraoccipital; posterior cranial fontanel very reduced or absent ..................................................................................... 15

- Adipose fin moderately long, its base about one-half as long as anal-fin base; medial groove of neurocranium mostly or exclusively on supraoccipital; posterior cranial fontanel conspicuous, long and narrow ... .............................................................................................................................................................. Arius

15. Lateral line bifurcated at caudal region; posterior cleithral process moderately long................. Plicofollis

- Lateral line not bifurcated at caudal region; posterior cleithral process very short..................... Cathorops

16. Lateral line not bifurcated at caudal region ............................................................................................. 17

- Lateral line bifurcated at caudal region ................................................................................................... 28

17. Temporal fossa present; fontanel limited by lateral ethmoid and frontal well developed, moderate to large .................................................................................................................................................................. 18

- Temporal fossa absent; fontanel limited by lateral ethmoid and frontal very reduced or inconspicuous..... .......................................................................................................................................................... Sciades

18. Medial groove of neurocranium limited by frontal and/or supraoccipital, rudimentary or absent............................................................................................. 19

- Medial groove of neurocranium limited by frontal and/or supraoccipital, very distinct...................................................... 22

19. Posterior cleithral process very short; posterior cranial fontanel very large ........................................... 20

- Posterior cleithral process moderately long; posterior cranial fontanel moderate to large ..................... 21

20. Accessory tooth plates absent..................................................................................................... Nedystoma

- Accessory tooth plates present.................................................................................................... Doiichthys

21. Posterior cranial fontanel oval and well developed; mesethmoid moderately wide at region of anterior nostrils................................................................................................................................... Potamosilurus

- Posterior cranial fontanel relatively long and narrow; mesethmoid very wide at region of anterior nostrils .................................................................................................................................................... Cochlefelis

22. Epioccipital not invading dorsal portion of cephalic shield .................................................................... 23

- Epioccipital invading dorsal portion of cephalic shield ................................................................ Carlarius

23. Adipose fin very short, its base less than one-half length of anal-fin base .............................................. 24

- Adipose fin moderately long, its length about half as long as anal-fin base ........................................... 25

24. Tooth plates associated with vomer present ............................................................................... Brustiarius

- Tooth plates associated with vomer absent ................................................................................. Cryptarius

25. Posterior cleithral process moderately long; medial groove of neurocranium limited by frontal bones, but also on supraoccipital; posterior cranial fontanel reduced or absent or long and narrow ................................................................................... 26

- Posterior cleithral process very short; medial groove of neurocranium limited mainly by supraoccipital; posterior cranial fontanel very large and oval .......................................................................... Nemapteryx

26. Posterior cranial fontanel well developed, long and narrow ................................................................... 27

- Posterior cranial fontanel very reduced or absent ......................................................................... Genidens

27. Tooth plates associated with vomer absent; accessory tooth plates very reduced or absent ..... Potamarius

- Tooth plates associated with vomer present; accessory tooth plates large .................................... Neoarius

28. Tooth plates associated with vomer absent; adipose fin moderately long, its length about half as long as anal-fin base ......................................................................................................................................... Arius

- Tooth plates associated with vomer present; adipose fin very short, its base less than one-half length of anal-fin base ..................................................................................................................................... Netuma

New classification of the Ariidae

Family Ariidae Bleeker, 1862

Amissidens Kailola, 2004

Amissidens hainesi (Kailola, 2000)

Amphiarius new genus

Amphiarius phrygiatus (Valenciennes, 1840)

Amphiarius rugispinis (Valenciennes, 1840)

Arius Valenciennes, 1840

Arius acutirostris Day, 1877 - sedis mutabilis

Arius africanus Günther, 1867 - sedis mutabilis

Arius arenarius ( Müller & Troschel, 1849) - sedis mutabilis

Arius arius (Hamilton, 1822)

Arius brunellii Zollezi, 1939 - sedis mutabilis

Arius burmanicus Day, 1870 - sedis mutabilis

Arius caelatus Valenciennes, 1840

Arius dispar Herre, 1926

Arius festinus Ng & Sparks, 2003 - sedis mutabilis

Arius gagora (Hamilton, 1822)

Arius jatius (Hamilton, 1822) - sedis mutabilis

Arius jella Day, 1877 - sedis mutabilis

Arius leptonotacanthus Bleeker, 1849 - sedis mutabilis

Arius macronotacanthus Bleeker, 1846 - sedis mutabilis

Arius maculatus (Thunberg, 1792)

Arius madagascariensis Vaillant, 1894

Arius malabaricus Day, 1877 - sedis mutabilis

Arius manillensis Valenciennes, 1840

Arius microcephalus Bleeker, 1855 - sedis mutabilis

Arius nenga (Hamilton, 1822) - sedis mutabilis

Arius oetik Bleeker, 1846 - sedis mutabilis

Arius subrostratus Valenciennes, 1840 - sedis mutabilis

Arius uncinatus Ng & Sparks, 2003 - sedis mutabilis

Arius venosus Valenciennes, 1840 - sedis mutabilis

Aspistor Jordan & Evermann, 1898

Aspistor luniscutis (Valenciennes, 1840)

Aspistor parkeri (Traill, 1832)

Bagre Cloquet, 1816

Bagre bagre (Linnaeus, 1766)

Bagre marinus (Mitchill, 1815)

Bagre panamensis (Gill, 1863)

Bagre pinnimaculatus (Steindachner, 1876)

Batrachocephalus Bleeker, 1846

Batrachocephalus mino (Hamilton, 1822)

Brustiarius Herre, 1935

Brustiarius nox (Herre, 1935)

Brustiarius proximus (Ogilby, 1898) - sedis mutabilis

Brustiarius solidus (Herre, 1935)

Carlarius new genus

Carlarius gigas (Boulenger, 1911) - sedis mutabilis

Carlarius heudelotii (Valenciennes, 1840)

Carlarius latiscutatus ( Günther, 1864)

Carlarius parkii ( Günther, 1864)

Cathorops Jordan & Gilbert, 1822

Cathorops agassizi (Eigenmann & Eigenmann, 1888)

Cathorops aguadulce (Meek, 1904)

Cathorops arenatus (Valenciennes, 1840)

Cathorops dasycephalus ( Günther, 1864)

Cathorops fuerthii (Steindachner, 1877)

Cathorops hypophthalmus (Steindachner, 1877)

Cathorops mapale Betancur-R. & Acero, 2005

Cathorops melanopus ( Günther, 1864)

Cathorops multiradiatus ( Günther, 1864)

Cathorops spixii (Agassiz, 1829)

Cathorops steindachneri (Gilbert & Starks, 1904)

Cathorops tuyra (Meek & Hildebrand, 1923)

Cephalocassis Bleeker, 1858

Cephalocassis bleekeri (Popta, 1900) - sedis mutabilis

Cephalocassis borneensis (Bleeker, 1851)

Cephalocassis manillensis (Valenciennes, 1840) - sedis mutabilis

Cephalocassis melanochir (Bleeker, 1852)

Cinetodus Ogilby, 1898

Cinetodus carinatus (Weber, 1913) - sedis mutabilis

Cinetodus froggatti (Ramsay & Ogilby, 1886)

Cochlefelis Whitley, 1941

Cochlefelis danielsi (Regan, 1908)

Cochlefelis dioctes (Kailola, 2000) - sedis mutabilis

Cochlefelis insidiator (Kailola, 2000) - sedis mutabilis

Cochlefelis spatula (Ramsay & Ogilby, 1886)

Cryptarius Kailola, 2004

Cryptarius daugueti (Chevey, 1932) - sedis mutabilis

Cryptarius truncatus (Valenciennes, 1840)

Doiichthys Weber, 1913

Doiichthys novaeguineae Weber, 1913

Galeichthys Valenciennes, 1840

Galeichthys ater Castelnau, 1861

Galeichthys feliceps Valenciennes, 1840

Galeichthys peruvianus Lütken, 1874 - sedis mutabilis

Genidens Castelnau, 1855

Genidens barbus ( Lacépède, 1803)

Genidens genidens (Cuvier, 1829)

Genidens machadoi (Miranda-Ribeiro, 1918)

Genidens planifrons (Higuchi, Reis & Araújo, 1982)

Hemiarius Bleeker, 1847

Hemiarius hardenbergi (Kailola, 2000) - sedis mutabilis

Hemiarius harmandi Sauvage, 1880 - sedis mutabilis

Hemiarius stormii (Bleeker, 1858)

Hemiarius sumatranus (Anonymous, 1830)

Hemiarius verrucosus (Ng, 2003) - sedis mutabilis

Ketengus Bleeker, 1847

Ketengus typus Bleeker, 1847

Nedystoma Ogilby, 1898

Nedystoma dayi (Ramsay & Ogilby, 1886)

Nemapteryx Ogilby, 1908

Nemapteryx armiger (De Vis, 1884)

Neoarius Castelnau, 1878

Neoarius augustus (Roberts, 1978) - sedis mutabilis

Neoarius berneyi (Whitley, 1941) - sedis mutabilis

Neoarius graeffei (Kner & Steindachner, 1867)

Neoarius midgleyi (Kailola & Pierce, 1988)

Neoarius pectoralis (Kailola, 2000) - sedis mutabilis

Netuma Bleeker, 1858

Netuma bilineatus (Valenciennes, 1840)

Netuma thalassinus ( Rüppell, 1837)

Notarius Gill, 1863

Notarius armbrusteri Betancur-R. & Acero, 2006 - sedis mutabilis

Notarius biffi Betancur-R. & Acero, 2004 - sedis mutabilis

Notarius cookei (Acero & Betancur-R., 2002) - sedis mutabilis

Notarius grandicassis (Valenciennes, 1840)

Notarius insculptus (Jordan & Gilbert, 1883) - sedis mutabilis

Notarius kessleri (Steindachner, 1877) - sedis mutabilis

Notarius lentiginosus (Eigenmann & Eigenmann, 1888)

Notarius neogranatensis (Acero & Betancur-R., 2002) - sedis mutabilis

Notarius osculus (Jordan & Gilbert, 1883) - sedis mutabilis

Notarius planiceps (Steindachner, 1877)

Notarius troschelii (Gill, 1863)

Osteogeneiosus Bleeker, 1846

Osteogeneiosus militaris (Linnaeus, 1758)

Pachyula Ogilby, 1898

Pachyula conorhynchus (Weber, 1913) - sedis mutabilis

Pachyula crassilabris (Ramsay & Ogilby, 1886)

Plicofollis Kailola, 2004

Plicofollis argyropleuron (Kuhl & van Hasselt, 1840)

Plicofollis crossocheilos (Bleeker, 1846) - sedis mutabilis

Plicofollis dussumieri (Valenciennes, 1840)

Plicofollis magatensis (Herre, 1926) - sedis mutabilis

Plicofollis nella (Valenciennes, 1840)

Plicofollis platystomus (Day, 1877) - sedis mutabilis

Plicofollis polystaphylodon (Bleeker, 1846)

Plicofollis tenuispinis (Day, 1877)

Potamarius Hubbs & Miller, 1960

Potamarius grandoculis (Steindachner, 1877)

Potamarius izabalensis Hubbs & Miller, 1960

Potamarius nelsoni (Evermann & Goldsborough, 1902)

Potamosilurus new genus

Potamosilurus coatesi (Kailola, 1990) - sedis mutabilis

Potamosilurus latirostris (Macleay, 1883)

Potamosilurus macrorhynchus (Weber, 1913)

Potamosilurus robertsi (Kailola, 1990) - sedis mutabilis

Potamosilurus velutinus (Weber, 1907) - sedis mutabilis

Sciades Müller & Troschel, 1849

Sciades assimilis ( Gùnther, 1864)

Sciades bonillai (Miles, 1945)

Sciades couma (Valenciennes, 1840)

Sciades dowii (Gill, 1863) - sedis mutabilis

Sciades emphysetus Müller & Troschel, 1849

Sciades felis (Linnaeus, 1766)

Sciades guatemalensis ( Günther, 1864)

Sciades herzbergii (Bloch, 1794)

Sciades leptaspis (Bleeker, 1862)

Sciades mastersi (Ogilby, 1898) - sedis mutabilis

Sciades passany (Valenciennes, 1840)

Sciades paucus (Kailola, 2000) - sedis mutabilis

Sciades platypogon ( Günther, 1864)

Sciades proops (Valenciennes, 1840)

Sciades sagor (Hamilton, 1822)

Sciades seemanni ( Günther, 1864)

Sciades sona (Hamilton, 1822) - sedis mutabilis

Sciades utarus (Kailola, 1990) - sedis mutabilis

Discussion and comparison with previous classifications

The results obtained in this study are of primary importance for the systematics and taxonomy of the Ariidae for a long time a matter of controversy and misunderstanding among ichthyologists worldwide. The characterization of the genera, definition of their limits and species composition has been a great challenge within the systematics of the Siluriformes. Presently about 130 species are recognized as valid, but many need to be better characterized taxonomically. The difficulties in recognizing species identity and monophyletic taxa are mainly due to the wide geographic distribution of the group and the overall similarity in the external morphology of their representatives coupled with lack of adequate series of specimens in museum collections. Thus studies aimed at more comprehensive approaches on systematics and phylogeny of the Ariidae have not been entirely successful because of the above mentioned constraints.

Recently Kailola (1990a, 2004), Betancur-R. & Mejía (2000), Betancur-R. (2003), Betancur-R. & Acero (2004) and Betancur-R. et al. (2004) based on the cladistic method, presented a preliminary analysis of the phylogenetic relationships of part of the genera and species of the Ariidae . Kailola (1990a) in an unpublished doctoral thesis discussed the relationships and zoogeography of the marine catfishes from New Guinea and Australia and Betancur-R. & Mejia (2000) and Betancur-R. (2003) did a similar study as part of the requirements for completion of the undergraduate program and a master’s dissertation respectively (not published) in Colombia and adjacent tropical waters. In both cases the authors examined only a geographically restricted subset of the recognized species and genera, limited to the areas above mentioned. Those studies included only a small number of species from African coasts, South America and Indian Ocean and did not redefine the complex genus Arius . The results obtained by Kailola (1990a) are essentially repeated in Kailola (2004) and the results obtained by Betancur-R. & Mejía (2000) are presented in Betancur-R. et al. (2004), but only part of the information contained in Betancur-R. (2003) is included in Betancur-R. & Acero (2004). In an unpublished Ph.D. study, Marceniuk (2003) included the largest number of ariid species ever assembled from different geographic areas of the world and used a vast array of morphological characters to study the systematics and phylogeny of the group.

The present work is based on the results obtained by Marceniuk (2003). All nominal genera are revised and redefined through exclusive osteological characters and a combination of internal and external morphological characters. Based on examination of the type-species the following genera are considered valid: Arius , Aspistor , Bagre Cloquet 1816, Batrachocephalus , Brustiarius , Cathorops , Cephalocassis , Cinetodus , Cochlefelis , Cryptarius , Doiichthys , Galeichthys , Genidens , Hemiarius , Ketengus , Nedystoma , Nemapteryx , Neoarius , Netuma , Notarius , Osteogeneiosus , Pachyula and Sciades . The genera Plicofollis and Potamarius are considered valid through examination of species morphologically similar to the type-species. Representative material of Amissidens species-type was not examined and the genus is recognized exclusively on the basis of evidences presented by Kailola (2004). Amphiarius , Carlarius and Potamosilurus are described as new genera. The nominal genera Ailurichthys , Anemanotus , Ariopsis , Bagre Oken 1817, Felichthys , Glanis , Guiritinga , Hemipimelodus , Hexanematichthys , Pseudarius , Sciadeichthys , Sciadeops , Selenaspis , Septobranchus and Stearopterus are considered junior synonyms based on examination of the type-species and Leptarius and Pararius are considered junior synonyms based on examination of the type-species not cleared and stained. Ariodes and Tetranesodon are considered junior synonyms based on data presented by Kailola (2004). Breviceps Swainson, 1838 and Mystus Gray, 1854 are junior homonyms of names available for the genus-group and thus rejected. Catastoma and Sarcogenys are considered nomina nuda and designated as synonyms of Netuma , in agreement with Kailola (2004). Glanide is not a Latin name and was not considered. The nominal genera Ancharius , Paradiplomystes and Tachysurus , previously included in the family are not recognized as members of the Ariidae .

The new classification proposed contains many modifications in relation to previous ones and the status of nominal genera as well as species composition are in many instances entirely changed. The species treated as sedis mutabilis (see New classification of the Ariidae ) were not examined and their inclusion in the respective genera is preliminary. In this section conflicts between the new and previous classifications are discussed and brief considerations about former concepts of genera and species composition are made. Classifications proposed by Kailola (2004), Betancur-R. & Acero (2004) and Betancur-R. et al. (2004) based on recognition of genera as monophyletic units as well as more recent and historically important classifications are discussed.

The genera Amissidens and Cryptarius are considered valid and the species included in them are those recognized by Kailola (2004). Previously C. truncatus was included in Arius (Burgess, 1989; Kottelat et al, 1993; Rainboth, 1996; Martin-Smith & Tan, 1998; Kailola, 1999; Tan & Ng, 2000; Kailola, 2000a; Ng, 2003) and C. daugueti in Hemipimelodus ( Désoutter, 1977; Rainboth, 1996).

Amphiarius is a new genus established to accommodate A. rugispinis and A. phrygiatus previously included in a distinct genus not formally named by Marceniuk (2003). In Marceniuk & Ferraris (2003) these two species were preliminary included in Arius , following Taylor & Menezes (1977), Burgess (1989), Cervigôn (1992), Le Bail et al. (2000), Camargo & Isaac (2001) and Acero (2003), decision also chosen by Kailola (2004) who examined only A. rugispinis , but suggested that they could be part of a separate genus she never designated. Betancur-R. & Acero (2004), however, considered A. rugispinis to belong in Notarius based on mitochondrial information.

One of the major problems in ariid systematics has been the delimitation of the genus Arius . It has been considered a very inclusive genus where ariid species not clearly defined were preliminary accommodated in the past. Kailola (1999) and Acero (2003) recognized Arius as a non monophyletic assemblage pointing out the enormous difficulty in defining the genus. Recent attempts to bring ariid generic concepts to a better understanding using phylogenetic systematics (Kailola, 2004; Betancur-R. & Acero, 2004) did not consider all the species tentatively included in Arius to circumscribe the genus or to define its monophyletic condition. As defined in the present study Arius is senior synonym of Ariodes and Pseudarius and include twenty one species occurring from eastern Africa and western Madagascar to south and southeast Asia. All the included species can be easily told apart from the remaining ariid species occurring in the Americas, New Guinea and Australia by the typical bifurcation of the lateral line at the caudal region reaching the bases of the upper and lower caudal-fin lobes (versus lateral line simple, not bifurcated at the caudal region reaching or not the bases of the upper caudal-fin lobe) except for the species of the genus Bagre in which, however, there are one pair of mental barbels (versus two pairs in the Arius species). Arius species are different from ariid species belonging to Indian Ocean genera by having the adipose fin of moderate length, about half as long as the anal fin (versus adipose fin short, less than half the length of the anal fin, characteristic of Netuma and Plicofollis ), maxillary barbels present and always developed (versus maxillary barbels absent in Batrachocephalus and rudimentary in Ketengus ) and mental barbels present (versus mental barbels absent in Osteogeneiosus ). The apomorphic or plesiomorphic condition of these characters as well as monophyly of Arius will be discussed in Marceniuk & Menezes (in preparation). In the present work only morphological features that are useful to distinguish the species of Arius from the species of the remaining genera are emphasized.

In Aspistor we recognize A. luniscutis and A. parkeri . Betancur-R. & Acero (2004) without examining the type-species, considered Aspistor as junior synonym of Notarius , admitting that Aspistor parkeri (= Arius quadriscutis ) would be the basal most species within Notarius , a condition that would justify its recognition as subgenus. Kailola (2004), based on data in Acero & Betancur-R. (2002a, 2002b) and Aguilera & de Aguilera (2004), recognized Aspistor as valid and included in it eight species from South and Central America and one from New Guinea. In her phylogenetic analysis she examined only Arius hardenbergi Kailola, 2000 considered in the present study to belong in Hemiarius . The remaining species included by Kailola (2004) in Aspistor , except A. luniscutis and A. parkeri are herein considered to belong in Notarius or Sciades . In older classifications A. luniscutis and A. parkeri are Arius species (Taylor & Menezes, 1977; Burgess, 1989; Cervigôn, 1992; Le Bail et al, 2000; Camargo & Isaac, 2001; Acero, 2003).

Bagre Cloquet, 1816 is senior synonym of Bagre Oken, 1817, Glanis , Stearopterus , Breviceps non Merrem, 1820, Felichthys (replacement for Breviceps ), Ailurichthys , Mystus non Scopoli, 1777 and Anemanotus following previous classifications (Castro-Aguirre et al., 1999; Marceniuk & Ferraris, 2003; Kailola, 2004). Very little changes have occurred in the species composition of the genus. In older publications the species were included either in Felichthys (Jordan & Evermann, 1896; Eigenmann, 1912; Meek & Hildebrand, 1923; Fowler, 1951) or in Ailurichthys ( Günther, 1864; Jordan & Gilbert, 1883; Eigenmann & Eigenmann, 1890; Regan, 1907) with the list of species included remaining essentially the same except for those herein considered as junior synonyms.

Batrachocephalus , Ketengus and Osteogeneiosus are considered valid as previously recognized by several authors (Jayaram & Dhanze, 1978; Jayaram, 1982, 1884; Jayaram & Dhanze, 1986; Talwar & Jhingran, 1991; Kottelat et al., 1993; Manilo & Bogorodsky, 2003; Kailola, 2004). The condition of monospecific genera is maintained due to the presence of a large number of exclusive characters in the respective type-species.

Brustiarius is considered senior synonym of Pararius and includes B. nox , B. proximus and B. solidus . Kailola (2004) recognized the monophyly of the genus, but did not include B. proximus that was considered to belong in Netuma , whereas Pararius was designated junior synonym of Netuma . In previous classifications Brustiarius was considered junior synonym or subgenus of Arius in which the species now in Brustiarius were included (Burgess, 1989; Kailola, 1990b, 1999, 2000b; Allen, 1991; Allen et al., 1992; Larson & Williams, 1997; Hutchins, 2001).

The ariid species from the African west coast formerly included in Arius (Fowler, 1936; Taylor, 1986, 1990; Burgess, 1989; Daget, 1992) are allocated into a new genus named Carlarius .

The species composition of Cathorops proposed by Marceniuk & Ferraris (2003) is maintained, including C. dasycephalus , recently referred to Arius (Bussing & Lopez, 1994; Kailola & Bussing, 1995; Betancur-R., 2003) or to Ariopsis (Nelson et al., 2004). Evidences that Cathorops is monophyletic are presented by Marceniuk (1997) based on the study of most species of the genus and this was confirmed by Betancur-R. et al. (2004) and Kailola (2004) although examining a restricted number of species.

Cephalocassis is recognized as senior synonym of Hemipimelodus and includes C. bleekeri , C. borneensis , C. manillensis and C. melanochir . Kailola (2004) agrees with the synonymy, but considers Cephalocassis represented only by C. borneensis and C. melanochir . C. bleekeri is included in Nemapteryx by Kailola (2004). Hemipimelodus , however, is considered valid by Désoutter (1977), Jayaram & Dhanze (1978), Jayaram (1982), Burgess (1989) and Roberts (1989).

Cinetodus and Pachyula are considered valid based on characters present in the respective type-species. Cinetodus is represented by C. carinatus and C. froggatti and Pachyula by P. crassilabris and P. conorhynchus . Kailola (2004) recognized Cinetodus and Pachyula synonyms and included all the species mentioned above in Cinetodus , but in Kailola’s phylogenetic analysis Cinetodus is considered paraphyletic not justifying the inclusion of the species in a single genus and contradicting this synonymy. The species herein included in Cinetodus and Pachyula were considered sister-species by Kailola (2004), a condition that would make the two genera valid (Marceniuk, 2003). The nominal genus Tetranesodon considered synonym of Cinetodus by Kailola (2004), is recognized by us as junior synonym of Pachyula .

Cochlefelis includes four species from southern New Guinea and northern Australia. The recognition of C. danielsi and C. spatula is in agreement with previous classifications (Roberts, 1978; Allen, 1991; Kailola, 2004). However, including C. dioctes formerly considered to belong in Arius (Ng, 2003) or in Hemiarius (Kailola, 2004) and C. insidiator , previously in Hemiarius (Kailola, 2004), represents a new arrangement. Kailola (2004) also included Arius burmanicus in Hemiarius considered by us to belong in Arius .

Nedystoma dayi and Doiichthys novaeguineae have been considered sister-species by Marceniuk (2003), a conclusion also reached by Kailola (2004) who considered Nedystoma senior synonym of Doiichthys . In the present paper the two genera are not considered synonyms. The respective type-species possess a large number of exclusive characters justifying their monospecific condition as previously recognized (Roberts, 1978; Burgess, 1989; Allen, 1991).

Galeichthys includes G. ater and G. felis from South Africa and G. peruvianus from the Peruvian coast in the Pacific Ocean, following previous classifications (Hildebrand, 1946; Taylor, 1986, 1990; Pequeño, 1989; Bianchi et al, 1993; Kailola & Bussing, 1995; Chirichigno & Vélez, 1998, Castro-Aguirre et al, 1999; Marceniuk& Ferraris, 2003; Heemstra & Heemstra, 2004; Nelson et al., 2004; Kailola, 2004). The species from east and west American coasts attributed to Galeichthys by Regan (1907) and Meek & Hildebrand (1923) are included in Cathorops , Notarius and Sciades .

Genidens was established and remained until very recently as a monospecific genus. As defined in this study it is senior synonym of Guiritinga and also includes Genidens barbus , G. planifions and G. machadoi following Marceniuk & Ferraris (2003) and Marceniuk (2005a, 2005b). In previous classifications G. barbus and G. planifions were part of Netuma (Figueiredo & Menezes, 1978; Higuchi et al., 1982; Burgess & Finley, 1996; Pequeño, 1997; López et al., 2002). Higuchi et al. (1982) questioned the inclusion of these species in Netuma hoping that in future systematic studies the name Guiritinga would be resurrected. Apparently Higuchi et al. (1982) expectations motivated Kailola (2004) to recognize Guiritinga to accommodate Genidens barbus and G. planifions . Guiritinga is not recognized by Kailola (2004) as a monophyletic group.

Hemiarius is considered a valid genus for H. hardenbergi , H. harmandi , H. stormii , H. sumatranus and H. verrucosus . Kailola (2004) based on the examination of H. stormii and two other species herein included in Cochlefelis ( C. dioctes and C. insidiator ) considered Hemiarius monophyletic. Hemiarius verrucosus , Notarius grandicassis and Sciades sona were additionally included in Hemiarius by Kailola (2004).

Our analysis indicates that Nemapteryx is monospecific. Kailola (2004) includes in this genus five species herein allocated to the genera Arius , Neoarius and Cephalocassis . As revealed by the topology of the consensus cladogram presented by Kailola (2004), the genus cannot be considered monophyletic.

Neoarius is resurrected and includes N. augustus , N. berneyi , N. graeffei , N. midgleyi and N. pectoralis all restricted to southern New Guinea and northern Australia. With exception of N. augustus , included by Kailola (2004) in Nemapteryx , the other species were considered by her to belong in Ariopsis .

Bagre thalassinus Rüppell, 1837 distributed from eastern Africa, south and southeast Asia to New Guinea and northern Australia (Kailola, 1986) is the type-species of Netuma . As defined by Kailola (2004) Netuma included N. bilineatus , Arius proximus (herein included in Brustiarius ) and N. thalassinus and is not monophyletic. In the present work only the species from the Indo-Pacific should be included in Netuma following Taylor (1986), Hutchins (2001) and Kailola (2004). The inclusion of species from the Western South Atlantic belonging to Genidens (Figueiredo & Menezes, 1978; Higuchi et al., 1982) and from the eastern and western American coasts belonging to Notarius and Sciades (Jordan & Evermann, 1898; Gilbert & Starks, 1904; Starks, 1906; Meek & Hildebrand, 1923) is not corroborated by us. Catastoma and Sarcogenys are considered nomina nuda and junior synonyms of Netuma as demonstrated by Kailola (2004).

Notarius is valid (Marceniuk & Ferraris, 2003; Betancur-R. & Acero, 2004) in disagreement with Kailola (2004) who recognizes Notarius as a junior synonym of Hemiarius . The species composition of the genus, however, differs from that presented by Betancur-R. & Acero (2004) by not including Amphiarius rugispinis and Aspistor parkeri (= Arius quadriscutis ) and adding Notarius osculus , considered by Betancur-R. & Acero (2004) as of uncertain status and included in previous classifications in Arius (Burgess, 1989; Bussing & López, 1994; Kailola & Bussing, 1995; Acero & Betancur-R., 2002a) or Hexanematichthys (Marceniuk & Ferraris, 2003). The nominal genus Sciadeops , recognized as junior synonym of Sciades by Kailola (2004), is considered junior synonym of Notarius .

Kailola (2004) described Plicofollis in which P. argyropleuron , P. crossocheilos , P. dussumieri , P. layardi (= Arius tenuispinis ), P. nella and P. polystaphilodon were included. We added into the genus P. platystomus that share with the other species of Plicofollis a unique combination of characters considered apomorphic by Marceniuk (2003).

Two species entirely confined to the freshwaters of North and Central America were allocated in Potamarius , a genus originally described by Hubbs & Miller (1960). Its type-species was previously included in Conorhynchus of the family Pimelodidae (Meek, 1904; Regan 1907). Potamarius grandoculis was considered to belong in Hexanematichthys by Figueiredo & Menezes (1978) and in Arius by Burgess (1989), but its inclusion in Potamarius is in agreement with previous classifications proposed by Marceniuk & Ferraris (2003) and Marceniuk, (2005b).

Potamosilurus is herein created for the species occurring exclusively in freshwater in New Guinea. P. coatesi , P. latirostris , P. macrorhynchus and P. robertsi are found in south-draining rivers and P. velutinus in north-draining rivers of New Guinea. With exception of P. macrorhynchus , recognized as incertae sedis, the remaining species were included in Ariopsis by Kailola (2004).

Hexanematichthys , Sciadeichthys , Selenaspis , Ariopsis and Leptarius are synonyms of Sciades , but have been recently considered either valid or placed in the synonymy of genera other than Sciades (Roberts, 1989; Kailola, 1990a; Castro-Aguirre et al., 1999; Acero, 2003; Marceniuk & Ferraris, 2003; Betancur-R. et al., 2004; Kailola, 2004). In this study the species belonging to Ariopsis (Acero, 2003; Kailola, 2004, in part), Hexanematichthys and Selenaspis (Acero, 2003; Betancur-R. et al., 2004; Kailola, 2004) and Arius (Betancur-R. et al., 2004, in part) are all included in Sciades based on the possession of the following exclusive characters within the Ariidae : otic capsules little developed; space between transcapular process and otic capsule very wide; temporal fossa very reduced or entirely closed; subvertebral process indistinct or little differentiated. Sciades was considered valid by Castro-Aguirre et al. (1999), whereas Marceniuk & Ferraris (2003) recognized this genus as probably senior synonym of Hexanematichthys . Kailola (2004) recognized Sciades based exclusively on examination of the type-species, considered by her sister-species of Hemiarius hardenbergi , additionally adding into the genus S. couma , S. herzbergii , S. dowii , S. parkeri , S. passany , S. proops and Notarius troschelii .