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The present study reports the first record of Sillago indica from the Iranian coast of the Oman Sea. Sixteen specimens were collected with beach seine during sampling in Chabahar Bay. The obtained detailed information on the morphometric and meristic characters is compared with previous records of S. indica. Morphological characters matched the previous description of this species. Molecular confirmation of the species identification was carried out using the partial mitochondrial cytochrome oxidase subunit I gene (COI). Genetic results revealed a 0.181-0.231 K2P distance with other sillaginid species. The identified haplotypes were identical with conspecific haplotypes in GenBank. [ABSTRACT FROM AUTHOR]

Migration independently evolved numerous times in animals, with a myriad of ecological and evolutionary implications. In fishes, perhaps the most extreme form of migration is diadromy, the migration between marine and freshwater environments. Key and long-standing questions are: how many times has diadromy evolved in fishes, how frequently do diadromous clades give rise to non-diadromous species, and does diadromy influence lineage diversification rates? Many diadromous fishes have large geographic ranges with constituent populations that use isolated freshwater habitats. This may limit gene flow between some populations, increasing the likelihood of speciation in diadromous lineages relative to nondiadromous lineages. Alternatively, diadromy may reduce lineage diversification rates if migration is associated with enhanced dispersal capacity that facilitates gene flow within and between populations. Clupeiformes (herrings, sardines, shads, and anchovies) is a model clade for testing hypotheses about the evolution of diadromy because it includes an exceptionally high proportion of diadromous species and several independent evolutionary origins of diadromy. However, relationships among major clupeiform lineages remain unresolved, and existing phylogenies sparsely sampled diadromous species, limiting the resolution of phylogenetically informed statistical analyses. We assembled a phylogenomic dataset and used multi-species coalescent and concatenation-based approaches to generate the most comprehensive, highly resolved clupeiform phylogeny to date, clarifying associations among several major clades and identifying recalcitrant relationships needing further examination. We determined that variation in rates of sequence evolution (heterotachy) and base-composition (nonstationarity) had little impact on our results. Using this phylogeny, we characterized evolutionary patterns of diadromy and tested for differences in lineage diversification rates between diadromous, marine, and freshwater lineages. We identified 13 transitions to diadromy, all during the Cenozoic Era (10 origins of anadromy, 2 origins of catadromy, and 1 origin of amphidromy), and 7 losses of diadromy. Two diadromous lineages rapidly generated nondiadromous species, demonstrating that diadromy is not an evolutionary dead end. We discovered considerably faster transition rates out of diadromy than to diadromy. The largest lineage diversification rate increase in Clupeiformes was associated with a transition to diadromy, but we uncovered little statistical support for categorically faster lineage diversification rates in diadromous versus nondiadromous fishes. We propose that diadromy may increase the potential for accelerated lineage diversification, particularly in species that migrate long distances. However, this potential may only be realized in certain biogeographic contexts, such as when diadromy allows access to ecosystems in which there is limited competition from incumbent species. [ABSTRACT FROM AUTHOR]

Harry hotlips (Plectorhinchus gibbosus), belonging to the fish family Haeumulidae, is recorded for the first time off the Iranian coast of the Oman Sea, Chabahar Bay (25°18′N, 60°37′E). Identification confirmed by comparing morphological data of the collected specimen with data of reported congener species off this area.

The first molecular evidence of the occurrence of Sillaginopodys chondropus from the Northern Coast of the Oman Sea is presented. Twenty-four specimens were collected with the beach seine during sampling in February 2021. A 573 bp haplotype of cytochrome oxidase subunit I gene (COI) revealed 0.18–0.25 K2P distance with other sillaginid species, while it was identical with conspecific haplotypes. Morphometric and meristic characters matched the previous description of S. chondropus. The length-weight relationship was W = 0.0025*TL3.363, suggesting positive allometric growth. All calculated length-length relationships were highly correlated (r²≥0.85). [ABSTRACT FROM AUTHOR]

The long-fin goatfish Upeneus supravittatus is recorded from the Iranian coast of the Oman Sea based on morphological and molecular (COI gene) identification. The species was recorded in the area based on two specimens collected from the Chabahar Bay (25° 18' N, 60° 37' E), Northern Oman Sea. [ABSTRACT FROM AUTHOR]

White sardine Escualosa thoracata (Valenciennes, 1847) was recorded for the first time from the Iranian coast of the Oman Sea. The identification was confirmed based on external morphometric and meristic characters, which were concordant with previously reported data. Genetic distances (based on 655 bp of COI Sequence) between identified and previously reported sequence were 0.8 % (p-distance). This record is a new addition to the ichthyofauna of the Oman Sea based on five specimens collected from Chabahar Bay. [ABSTRACT FROM AUTHOR]

The pugnose ponyfish Secutor ruconius is recorded for the first time from the Persian Gulf and the Gulf of Oman. The identification was confirmed based on morphological characteristics and 668 bp sequence of COI mtDNA. The species record is a new addition to the ichthyofauna of this area, resulting from specimens being collected from the Northern Qeshm Island (N 26°57', E 55°45'E) in the Persian Gulf and in the Chabahar Bay (N 25°18', E 60°37') in the Northern Oman Gulf. [ABSTRACT FROM AUTHOR]

The burrowing goby, Trypauchen vagina, is recorded for the first time from the Iranian coast of the Persian Gulf. Only one other record is known for this species from the Persian Gulf; that record is from Kuwait. The subject record is a new addition to the ichthyofauna of Iran resulting from four T. vagina specimens being collected from north of Qeshm Island in the Khoran Strait (26°56'N, 55°54'E) in the Persian Gulf. [ABSTRACT FROM AUTHOR]

Length-weight relationships and fecundity of 93 individual female Acipenser persicus broodstocks were investigated. The specimens were caught during 2001- 2005 from Golestan, Mazandaran and Guilan provinces along the southern coast of the Caspian Sea. Total length and weight of each fish was measured to the nearest 1cm and 100 g, respectively. Age determination was carried out by using transects of the first ray of pectoral fin. The absolute fecundity was assessed by egg count per weight unit of all eggs existed in the body. The specimens were from 13 to 20 years old, of which the 16 years old had the highest proportion with 23.7%. Range of total length and weight were 132.5 to 211 cm and 14 to 42 kg, respectively. Mean absolute fecundity was estimated 267810 ± 92570. Total length, weight and absolute fecundity of fish increased with age in all cases, showed a significant positive correlation (p <0.01). The slope of the length-weight relationship (b) was equal to 2.745 and isometric growth pattern was determined in this species. [ABSTRACT FROM AUTHOR]

Length-weight relationship (LWR) and length-length relationship (LLR) were estimated for six species of ponyfishes captured in the Persian Gulf, Iran. The LWRs indicated isometric growth in ornate ponyfish (Equulites lineolatus), common ponyfish (Leiognathus equulus) and deep pugnose ponyfish (Secutor ruconius) species, positive allometric growth in striped ponyfish (Aurigequula fasciata) and negative allometric growth in decorated ponyfish (Nuchequula gerreoides) and orangefin ponyfish (Photopectoralis bindus). LWR and LLR parameters for one of the species (E. lineolatus) are given for the first time. The relationships between TL, FL and SL were all linear and highly correlated (for all cases: r2 > 0.97). [ABSTRACT FROM AUTHOR]

Taillessness (absence of the caudal fin and some of the caudal peduncle) and skeletal deformity is described in 2 striped piggy Pomadasys stridens (Haemulidae) specimens collected from the Persian Gulf along the coast of Hormuz Island, Iran. Deformed specimens were entirely missing caudal fins along with at least 1 caudal vertebra, caudal portions of vertebral columns were bent dorsoventrally, posterior sections of swim bladders were reduced in size, and caudal vertebral centra were compacted anteroposteriorly in 1 individual. Environmental conditions in the Persian Gulf may be responsible for these deformities, but genetic causes cannot be entirely ruled out.